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Li J, Chen Y, Wang L, Li D, Liu L, Li M. An ethylene response factor AcERF116 identified from A. catechu is involved in fruitlet abscission. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 344:112091. [PMID: 38615719 DOI: 10.1016/j.plantsci.2024.112091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/16/2024]
Abstract
Procedural abscission of outer reproductive organs during flower and fruit development occurs in most plant lineages. Undesired abscission, such as fruitlet shedding causes considerable yield loss in many fruit-producing species. Ethylene is one of the key factors regulating organ abscission. However, the participants involved in the ethylene-mediated abscission pathway remains largely unidentified. In this study, we focused on the ethylene response transcription factors (ERFs) regulating fruitlet abscission in an industrial tree species, A. catechu. A total of 165 ERF genes have been found in the A. catechu genome and eight of these showed distinct expression between the "about-to-abscise" and "non-abscised" samples. An AcERF116 gene with high expression level in the fruit abscission zone (FAZ) was selected for further study. Overexpression of the AcERF116 gene accelerated cell separation in the abscission zone (AZ) and promoted pedicel abscission in transgenic tomato lines. The PG (ploygalacturonase) activity was enhanced in the FAZs of A. catechu fruitlets during ethylene-induced fruitlet abscission, while the PME (pectin methylesterase) activity was suppressed. In addition, cytosolic alkalization was observed in the AZs during abscission in both tomato and A. catechu. Our results suggest that AcERF116 plays a critical role in the crosstalk of ethylene and fruitlet abscission in A. catechu.
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Affiliation(s)
- Jia Li
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan 571339, PR China
| | - Yunche Chen
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan 571339, PR China; College of Life Sciences, Chongqing Normal University, Chongqing 401331, PR China
| | - Linkai Wang
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan 571339, PR China
| | - Dongxia Li
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan 571339, PR China
| | - Liyun Liu
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang, Hainan 571339, PR China.
| | - Meng Li
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, PR China.
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2
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He Z, Ma X, Wang F, Li J, Zhao M. LcERF10 functions as a positive regulator of litchi fruitlet abscission. Int J Biol Macromol 2023; 250:126264. [PMID: 37572813 DOI: 10.1016/j.ijbiomac.2023.126264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/14/2023]
Abstract
Phytohormone ethylene is well-known in positive modulation of plant organ abscission. However, the molecular mechanism underlying ethylene-induced abscission remains largely unknown. Here, we identified an ethylene-responsive factor, LcERF10, as a key regulatory gene in litchi fruitlet abscission. LcERF10 was strongly induced in the fruitlet abscission zone (FAZ) during the ethylene-activated abscission. Silencing of LcERF10 in litchi weakened the cytosolic alkalization of the FAZ and reduced fruitlet abscission. Moreover, LcERF10 directly bound the promoter and repressed the expression of LcNHX7, a Na+/H+ exchanger that was down-regulated in FAZ following the ethylene-activated abscission and up-regulated after LcERF10 silencing. Additionally, ectopic expression of LcERF10 in Arabidopsis promoted the cytosolic alkalization of the floral organ AZ and accelerated the floral organ abscission. Collectively, our results suggest that the transcription factor LcERF10 plays a positive role in litchi fruitlet abscission.
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Affiliation(s)
- Zidi He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Xingshuai Ma
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Fei Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Jianguo Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
| | - Minglei Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
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3
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Ma X, Xie X, He Z, Wang F, Fan R, Chen Q, Zhang H, Huang Z, Wu H, Zhao M, Li J. A LcDOF5.6-LcRbohD regulatory module controls the reactive oxygen species-mediated fruitlet abscission in litchi. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 113:954-968. [PMID: 36587275 DOI: 10.1111/tpj.16092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 06/17/2023]
Abstract
Reactive oxygen species (ROS) have been emerging as a key regulator in plant organ abscission. However, the mechanism underlying the regulation of ROS homeostasis in the abscission zone (AZ) is not completely established. Here, we report that a DOF (DNA binding with one finger) transcription factor LcDOF5.6 can suppress the litchi fruitlet abscission through repressing the ROS accumulation in fruitlet AZ (FAZ). The expression of LcRbohD, a homolog of the Arabidopsis RBOHs that are critical for ROS production, was significantly increased during the litchi fruitlet abscission, in parallel with an increased accumulation of ROS in FAZ. In contrast, silencing of LcRbohD reduced the ROS accumulation in FAZ and decreased the fruitlet abscission in litchi. Using in vitro and in vivo assays, we revealed that LcDOF5.6 was shown to inhibit the expression of LcRbohD via direct binding to its promoter. Consistently, silencing of LcDOF5.6 increased the expression of LcRbohD, concurrently with higher ROS accumulation in FAZ and increased fruitlet abscission. Furthermore, the expression of key genes (LcIDL1, LcHSL2, LcACO2, LcACS1, and LcEIL3) in INFLORESCENCE DEFICIENT IN ABSCISSION signaling and ethylene pathways were altered in LcRbohD-silenced and LcDOF5.6-silenced FAZ cells. Taken together, our results demonstrate an important role of the LcDOF5.6-LcRbohD module during litchi fruitlet abscission. Our findings provide new insights into the molecular regulatory network of organ abscission.
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Affiliation(s)
- Xingshuai Ma
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Xianlin Xie
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Zidi He
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Fei Wang
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Ruixin Fan
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Qingxin Chen
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Hang Zhang
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Zhiqiang Huang
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Hong Wu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
| | - Minglei Zhao
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Jianguo Li
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
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Zhao Y, Wang J, Huang W, Zhang D, Wu J, Li B, Li M, Liu L, Yan M. Abscisic-Acid-Regulated Responses to Alleviate Cadmium Toxicity in Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:1023. [PMID: 36903884 PMCID: PMC10005406 DOI: 10.3390/plants12051023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/12/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
High levels of cadmium (Cd) in soil can cause crop yield reduction or death. Cadmium accumulation in crops affects human and animal health as it passes through the food chain. Therefore, a strategy is needed to enhance the tolerance of crops to this heavy metal or reduce its accumulation in crops. Abscisic acid (ABA) plays an active role in plants' response to abiotic stress. The application of exogenous ABA can reduce Cd accumulation in shoots of some plants and enhance the tolerance of plants to Cd; therefore, ABA may have good application prospects. In this paper, we reviewed the synthesis and decomposition of ABA, ABA-mediated signal transduction, and ABA-mediated regulation of Cd-responsive genes in plants. We also introduced physiological mechanism underlying Cd tolerance because of ABA. Specifically, ABA affects metal ion uptake and transport by influencing transpiration and antioxidant systems, as well as by affecting the expression of metal transporter and metal chelator protein genes. This study may provide a reference for further research on the physiological mechanism of heavy metal tolerance in plants.
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Affiliation(s)
- Yuquan Zhao
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Jiaqi Wang
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Wei Huang
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Dawei Zhang
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Jinfeng Wu
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Bao Li
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Mei Li
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Lili Liu
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Mingli Yan
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
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5
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Ye C, He Z, Peng J, Wang R, Wang X, Fu M, Zhang Y, Wang A, Liu Z, Jia G, Chen Y, Tian B. Genomic and genetic advances of oiltea-camellia ( Camellia oleifera). FRONTIERS IN PLANT SCIENCE 2023; 14:1101766. [PMID: 37077639 PMCID: PMC10106683 DOI: 10.3389/fpls.2023.1101766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/22/2023] [Indexed: 05/03/2023]
Abstract
Oiltea-camellia (C. oleifera) is a widely cultivated woody oil crop in Southern China and Southeast Asia. The genome of oiltea-camellia was very complex and not well explored. Recently, genomes of three oiltea-camellia species were sequenced and assembled, multi-omic studies of oiltea-camellia were carried out and provided a better understanding of this important woody oil crop. In this review, we summarized the recent assembly of the reference genomes of oiltea-camellia, genes related to economic traits (flowering, photosynthesis, yield and oil component), disease resistance (anthracnose) and environmental stress tolerances (drought, cold, heat and nutrient deficiency). We also discussed future directions of integrating multiple omics for evaluating genetic resources and mining key genes of important traits, and the application of new molecular breeding and gene editing technologies to accelerate the breeding process of oiltea-camellia.
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Affiliation(s)
- Changrong Ye
- Academy of Innovation and Research, Huazhi Biotechnology Co. Ltd., Changsha, China
| | - Zhilong He
- Research Institute of Oil Tea Camellia, Hunan Academy of Forestry, Changsha, China
| | - Jiayu Peng
- Academy of Innovation and Research, Huazhi Biotechnology Co. Ltd., Changsha, China
| | - Rui Wang
- Research Institute of Oil Tea Camellia, Hunan Academy of Forestry, Changsha, China
| | - Xiangnan Wang
- Research Institute of Oil Tea Camellia, Hunan Academy of Forestry, Changsha, China
| | - Mengjiao Fu
- Department of Research and Development, Mountain Yuelu Breeding Innovation Center, Changsha, China
| | - Ying Zhang
- Research Institute of Oil Tea Camellia, Hunan Academy of Forestry, Changsha, China
| | - Ai Wang
- Department of Research and Development, Mountain Yuelu Breeding Innovation Center, Changsha, China
| | - Zhixian Liu
- Department of Research and Development, Mountain Yuelu Breeding Innovation Center, Changsha, China
| | - Gaofeng Jia
- Academy of Innovation and Research, Huazhi Biotechnology Co. Ltd., Changsha, China
- Department of Research and Development, Mountain Yuelu Breeding Innovation Center, Changsha, China
- *Correspondence: Gaofeng Jia, ; Yongzhong Chen, ; Bingchuan Tian,
| | - Yongzhong Chen
- Research Institute of Oil Tea Camellia, Hunan Academy of Forestry, Changsha, China
- *Correspondence: Gaofeng Jia, ; Yongzhong Chen, ; Bingchuan Tian,
| | - Bingchuan Tian
- Academy of Innovation and Research, Huazhi Biotechnology Co. Ltd., Changsha, China
- Department of Research and Development, Mountain Yuelu Breeding Innovation Center, Changsha, China
- *Correspondence: Gaofeng Jia, ; Yongzhong Chen, ; Bingchuan Tian,
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Cheng L, Li R, Wang X, Ge S, Wang S, Liu X, He J, Jiang CZ, Qi M, Xu T, Li T. A SlCLV3-SlWUS module regulates auxin and ethylene homeostasis in low light-induced tomato flower abscission. THE PLANT CELL 2022; 34:4388-4408. [PMID: 35972422 PMCID: PMC9614458 DOI: 10.1093/plcell/koac254] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/03/2022] [Indexed: 06/12/2023]
Abstract
Premature abscission of flowers and fruits triggered by low light stress can severely reduce crop yields. However, the underlying molecular mechanism of this organ abscission is not fully understood. Here, we show that a gene (SlCLV3) encoding CLAVATA3 (CLV3), a peptide hormone that regulates stem cell fate in meristems, is highly expressed in the pedicel abscission zone (AZ) in response to low light in tomato (Solanum lycopersicum). SlCLV3 knockdown and knockout lines exhibit delayed low light-induced flower drop. The receptor kinases SlCLV1 and BARELY ANY MERISTEM1 function in the SlCLV3 peptide-induced low light response in the AZ to decrease expression of the transcription factor gene WUSCHEL (SlWUS). DNA affinity purification sequencing identified the transcription factor genes KNOX-LIKE HOMEDOMAIN PROTEIN1 (SlKD1) and FRUITFULL2 (SlFUL2) as SlWUS target genes. Our data reveal that low light reduces SlWUS expression, resulting in higher SlKD1 and SlFUL2 expression in the AZ, thereby perturbing the auxin response gradient and causing increased ethylene production, eventually leading to the initiation of abscission. These results demonstrate that the SlCLV3-SlWUS signaling pathway plays a central role in low light-induced abscission by affecting auxin and ethylene homeostasis.
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Affiliation(s)
- Lina Cheng
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Ruizhen Li
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Xiaoyang Wang
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Siqi Ge
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Sai Wang
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Xianfeng Liu
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Jing He
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Cai-Zhong Jiang
- Crops Pathology and Genetic Research Unit, United States Department of Agriculture Agricultural Research Service, Albany, California 95616, USA
- Department of Plant Sciences, University of California, Los Angeles, California 95616, USA
| | - Mingfang Qi
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Tao Xu
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
| | - Tianlai Li
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China
- Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, China
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Crick J, Corrigan L, Belcram K, Khan M, Dawson JW, Adroher B, Li S, Hepworth SR, Pautot V. Floral organ abscission in Arabidopsis requires the combined activities of three TALE homeodomain transcription factors. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6150-6169. [PMID: 35689803 DOI: 10.1093/jxb/erac255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Floral organ abscission is a separation process in which sepals, petals, and stamens detach from the plant at abscission zones. Here, we investigated the collective role of three amino-acid-loop-extension (TALE) homeobox genes ARABIDOPSIS THALIANA HOMEOBOX GENE1 (ATH1), KNAT6 (for KNOTTED LIKE from Arabidopsis thaliana) and KNAT2, which form a module that patterns boundaries under the regulation of BLADE-ON-PETIOLE 1 and 2 (BOP1/2) co-activators. These TALE homeodomain transcription factors were shown to maintain boundaries in the flower, functioning as a unit to coordinate the growth, patterning, and activity of abscission zones. Together with BOP1 and BOP2, ATH1 and its partners KNAT6 and KNAT2 collectively contribute to the differentiation of lignified and separation layers of the abscission zone. The genetic interactions of BOP1/2 and ATH1 with INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) were also explored. We showed that BOP1/2 co-activators and ATH1 converge with the IDA signalling pathway to promote KNAT6 and KNAT2 expression in the abscission zone and cell separation. ATH1 acts as a central regulator in floral organ abscission as it controls the expression of other TALE genes in abscission zone cells.
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Affiliation(s)
- Jennifer Crick
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Laura Corrigan
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Katia Belcram
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Madiha Khan
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Jeff W Dawson
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Bernard Adroher
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Sibei Li
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | | | - Véronique Pautot
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
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8
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Sriskantharajah K, El Kayal W, Torkamaneh D, Ayyanath MM, Saxena PK, Sullivan AJ, Paliyath G, Subramanian J. Transcriptomics of Improved Fruit Retention by Hexanal in 'Honeycrisp' Reveals Hormonal Crosstalk and Reduced Cell Wall Degradation in the Fruit Abscission Zone. Int J Mol Sci 2021; 22:ijms22168830. [PMID: 34445535 PMCID: PMC8396267 DOI: 10.3390/ijms22168830] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 12/13/2022] Open
Abstract
Apples (Malus domestica Borkh) are prone to preharvest fruit drop, which is more pronounced in 'Honeycrisp'. Hexanal is known to improve fruit retention in several economically important crops. The effects of hexanal on the fruit retention of 'Honeycrisp' apples were assessed using physiological, biochemical, and transcriptomic approaches. Fruit retention and fruit firmness were significantly improved by hexanal, while sugars and fresh weight did not show a significant change in response to hexanal treatment. At commercial maturity, abscisic acid and melatonin levels were significantly lower in the treated fruit abscission zone (FAZ) compared to control. At this stage, a total of 726 differentially expressed genes (DEGs) were identified between treated and control FAZ. Functional classification of the DEGs showed that hexanal downregulated ethylene biosynthesis genes, such as S-adenosylmethionine synthase (SAM2) and 1-aminocyclopropane-1-carboxylic acid oxidases (ACO3, ACO4, and ACO4-like), while it upregulated the receptor genes ETR2 and ERS1. Genes related to ABA biosynthesis (FDPS and CLE25) were also downregulated. On the contrary, key genes involved in gibberellic acid biosynthesis (GA20OX-like and KO) were upregulated. Further, hexanal downregulated the expression of genes related to cell wall degrading enzymes, such as polygalacturonase (PG1), glucanases (endo-β-1,4-glucanase), and expansins (EXPA1-like, EXPA6, EXPA8, EXPA10-like, EXPA16-like). Our findings reveal that hexanal reduced the sensitivity of FAZ cells to ethylene and ABA. Simultaneously, hexanal maintained the cell wall integrity of FAZ cells by regulating genes involved in cell wall modifications. Thus, delayed fruit abscission by hexanal is most likely achieved by minimizing ABA through an ethylene-dependent mechanism.
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Affiliation(s)
- Karthika Sriskantharajah
- Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, ON N1G2W1, Canada; (K.S.); (D.T.); (M.M.A.); (P.K.S.); (A.J.S.); (G.P.)
| | - Walid El Kayal
- Department of Plant Agriculture, University of Guelph-Vineland Station, 4890 Victoria Ave N, Vineland, ON L0R2E0, Canada;
- Faculty of Agricultural and Food Science, American University of Beirut, Riad El Solh, P.O. Box 11-0236, Beirut 1107 2020, Lebanon
| | - Davoud Torkamaneh
- Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, ON N1G2W1, Canada; (K.S.); (D.T.); (M.M.A.); (P.K.S.); (A.J.S.); (G.P.)
- Faculté des Sciences de l’Agriculture et de l’alimentation, Universite Laval, Pavillon Paul-Comtois, 2425, rue de l’Agriculture, Local 1122, Québec City, QC G1V 0A6, Canada
| | - Murali M. Ayyanath
- Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, ON N1G2W1, Canada; (K.S.); (D.T.); (M.M.A.); (P.K.S.); (A.J.S.); (G.P.)
| | - Praveen K. Saxena
- Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, ON N1G2W1, Canada; (K.S.); (D.T.); (M.M.A.); (P.K.S.); (A.J.S.); (G.P.)
| | - Alan J. Sullivan
- Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, ON N1G2W1, Canada; (K.S.); (D.T.); (M.M.A.); (P.K.S.); (A.J.S.); (G.P.)
| | - Gopinadhan Paliyath
- Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, ON N1G2W1, Canada; (K.S.); (D.T.); (M.M.A.); (P.K.S.); (A.J.S.); (G.P.)
| | - Jayasankar Subramanian
- Department of Plant Agriculture, University of Guelph-Vineland Station, 4890 Victoria Ave N, Vineland, ON L0R2E0, Canada;
- Correspondence: ; Tel.: +1-905-562-4141 (ext. 134)
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Hu X, Yang M, Gong S, Li H, Zhang J, Sajjad M, Ma X, Yuan D. Ethylene-regulated immature fruit abscission is associated with higher expression of CoACO genes in Camellia oleifera. ROYAL SOCIETY OPEN SCIENCE 2021; 8:202340. [PMID: 34109038 PMCID: PMC8170184 DOI: 10.1098/rsos.202340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Immature fruit abscission is a key limiting factor in Camellia oleifera Abel. (C. oleifera) yield. Ethylene is considered to be an important phytohormone in regulating fruit abscission. However, the molecular mechanism of ethylene in regulating fruit abscission in C. oleifera has not yet been studied. Here, we found that the 1-aminocyclopropane-1-carboxylic acid (ACC) content was significantly increased in the abscission zones (AZs) of abnormal fruits (AF) which were about to abscise when compared with normal fruits (NF) in C. oleifera 'Huashuo'. Furthermore, exogenous ethephon treatment stimulated fruit abscission. The cumulative rates of fruit abscission in ethephon-treated fruits (ETH-F) on the 4th (35.0%), 8th (48.7%) and 16th (57.7%) days after treatment (DAT) were significantly higher than the control. The ACC content and 1-aminocyclopropane-1-carboxylate oxidase (ACO) activity in AZs of ETH-F were also significantly increased when compared with NF on the 4th and 8th DAT. CoACO1 and CoACO2 were isolated in C. oleifera for the first time. The expressions of CoACO1 and CoACO2 were considerably upregulated in AZs of AF and ETH-F. This study suggested that ethylene played an important role in immature fruit abscission of C. oleifera and the two CoACOs were the critical genes involved in ethylene's regulatory role.
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Affiliation(s)
- Xiao Hu
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education and the Key Laboratory of Non-Wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
| | - Mi Yang
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education and the Key Laboratory of Non-Wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
| | - Shoufu Gong
- Xinyang Agriculture and Forestry University, Xinyang 464000, People's Republic of China
| | - Hongbo Li
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education and the Key Laboratory of Non-Wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
| | - Jian Zhang
- Xinyang Agriculture and Forestry University, Xinyang 464000, People's Republic of China
| | - Muhammad Sajjad
- Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Islamabad 45550, Pakistan
| | - Xiaoling Ma
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education and the Key Laboratory of Non-Wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
| | - Deyi Yuan
- Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education and the Key Laboratory of Non-Wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
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10
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Du J, Lu S, Chai M, Zhou C, Sun L, Tang Y, Nakashima J, Kolape J, Wen Z, Behzadirad M, Zhong T, Sun J, Zhang Y, Wang Z. Functional characterization of PETIOLULE-LIKE PULVINUS (PLP) gene in abscission zone development in Medicago truncatula and its application to genetic improvement of alfalfa. PLANT BIOTECHNOLOGY JOURNAL 2021; 19:351-364. [PMID: 32816361 PMCID: PMC7868985 DOI: 10.1111/pbi.13469] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/29/2020] [Accepted: 08/07/2020] [Indexed: 05/05/2023]
Abstract
Alfalfa (Medicago sativa L.) is one of the most important forage crops throughout the world. Maximizing leaf retention during the haymaking process is critical for achieving superior hay quality and maintaining biomass yield. Leaf abscission process affects leaf retention. Previous studies have largely focused on the molecular mechanisms of floral organ, pedicel and seed abscission but scarcely touched on leaf and petiole abscission. This study focuses on leaf and petiole abscission in the model legume Medicago truncatula and its closely related commercial species alfalfa. By analysing the petiolule-like pulvinus (plp) mutant in M. truncatula at phenotypic level (breakstrength and shaking assays), microscopic level (scanning electron microscopy and cross-sectional analyses) and molecular level (expression level and expression pattern analyses), we discovered that the loss of function of PLP leads to an absence of abscission zone (AZ) formation and PLP plays an important role in leaflet and petiole AZ differentiation. Microarray analysis indicated that PLP affects abscission process through modulating genes involved in hormonal homeostasis, cell wall remodelling and degradation. Detailed analyses led us to propose a functional model of PLP in regulating leaflet and petiole abscission. Furthermore, we cloned the PLP gene (MsPLP) from alfalfa and produced RNAi transgenic alfalfa plants to down-regulate the endogenous MsPLP. Down-regulation of MsPLP results in altered pulvinus structure with increased leaflet breakstrength, thus offering a new approach to decrease leaf loss during alfalfa haymaking process.
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Affiliation(s)
- Juan Du
- Noble Research InstituteArdmoreOKUSA
- Institute for Agricultural BiosciencesOklahoma State UniversityArdmoreOKUSA
- College of Grassland Science and TechnologyChina Agricultural UniversityBeijingChina
| | - Shaoyun Lu
- College of Life SciencesSouth China Agricultural UniversityGuangzhouChina
| | - Maofeng Chai
- Noble Research InstituteArdmoreOKUSA
- Grassland Agri‐Husbandry Research CenterCollege of Grassland ScienceQingdao Agricultural UniversityQingdaoChina
| | - Chuanen Zhou
- School of Life ScienceShandong UniversityQingdaoChina
| | - Liang Sun
- Noble Research InstituteArdmoreOKUSA
| | | | | | - Jaydeep Kolape
- Noble Research InstituteArdmoreOKUSA
- Morrison Microscopy Core Research FacilityCenter for BiotechnologyUniversity of Nebraska‐LincolnNEUSA
| | - Zhaozhu Wen
- Noble Research InstituteArdmoreOKUSA
- College of AgricultureHunan Agricultural UniversityHunanChina
| | - Marjan Behzadirad
- Institute for Agricultural BiosciencesOklahoma State UniversityArdmoreOKUSA
| | - Tianxiu Zhong
- College of Forestry and Landscape ArchitectureSouth China Agricultural UniversityGuangzhouChina
| | - Juan Sun
- Grassland Agri‐Husbandry Research CenterCollege of Grassland ScienceQingdao Agricultural UniversityQingdaoChina
| | - Yunwei Zhang
- College of Grassland Science and TechnologyChina Agricultural UniversityBeijingChina
| | - Zeng‐Yu Wang
- Noble Research InstituteArdmoreOKUSA
- Grassland Agri‐Husbandry Research CenterCollege of Grassland ScienceQingdao Agricultural UniversityQingdaoChina
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11
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Expression Kinetics of Regulatory Genes Involved in the Vesicle Trafficking Processes Operating in Tomato Flower Abscission Zone Cells during Pedicel Abscission. Life (Basel) 2020; 10:life10110273. [PMID: 33172002 PMCID: PMC7694662 DOI: 10.3390/life10110273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 01/19/2023] Open
Abstract
The abscission process occurs in a specific abscission zone (AZ) as a consequence of the middle lamella dissolution, cell wall degradation, and formation of a defense layer. The proteins and metabolites related to these processes are secreted by vesicle trafficking through the plasma membrane to the cell wall and middle lamella of the separating cells in the AZ. We investigated this process, since the regulation of vesicle trafficking in abscission systems is poorly understood. The data obtained describe, for the first time, the kinetics of the upregulated expression of genes encoding the components involved in vesicle trafficking, occurring specifically in the tomato (Solanum lycopersicum) flower AZ (FAZ) during pedicel abscission induced by flower removal. The genes encoding vesicle trafficking components included soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), SNARE regulators, and small GTPases. Our results clearly show how the processes of protein secretion by vesicle trafficking are regulated, programmed, and orchestrated at the level of gene expression in the FAZ. The data provide evidence for target proteins, which can be further used for affinity purification of plant vesicles in their natural state. Such analyses and dissection of the complex vesicle trafficking networks are essential for further elucidating the mechanism of organ abscission.
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Parra R, Paredes MA, Labrador J, Nunes C, Coimbra MA, Fernandez-Garcia N, Olmos E, Gallardo M, Gomez-Jimenez MC. Cell Wall Composition and Ultrastructural Immunolocalization of Pectin and Arabinogalactan Protein during Olea europaea L. Fruit Abscission. PLANT & CELL PHYSIOLOGY 2020; 61:814-825. [PMID: 32016408 DOI: 10.1093/pcp/pcaa009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 01/24/2020] [Indexed: 06/10/2023]
Abstract
Cell wall modification is integral to many plant developmental processes where cells need to separate, such as abscission. However, changes in cell wall composition during natural fruit abscission are poorly understood. In olive (Olea europaea L.), some cultivars such as 'Picual' undergo massive natural fruit abscission after fruit ripening. This study investigates the differences in cell wall polysaccharide composition and the localization of pectins and arabinogalactan protein (AGP) in the abscission zone (AZ) during cell separation to understand fruit abscission control in 'Picual' olive. To this end, immunogold labeling employing a suite of monoclonal antibodies to cell wall components (JIM13, LM5, LM6, LM19 and LM20) was investigated in olive fruit AZ. Cell wall polysaccharide extraction revealed that the AZ cell separation is related to the de-esterification and degradation of pectic polysaccharides. Moreover, ultrastructural localization showed that both esterified and unesterified homogalacturonans (HGs) localize mainly in the AZ cell walls, including the middle lamella and tricellular junction zones. Our results indicate that unesterified HGs are likely to contribute to cell separation in the olive fruit AZ. Similarly, immunogold labeling demonstrated a decrease in both galactose-rich and arabinose-rich pectins in AZ cell walls during ripe fruit abscission. In addition, AGPs were localized in the cell wall, plasma membrane and cytoplasm of AZ cells with lower levels of AGPs during ripe fruit abscission. This detailed temporal profile of the cell wall polysaccharide composition, and the pectins and AGP immunolocalization in the olive fruit AZ, offers new insights into cell wall remodeling during ripe fruit abscission.
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Affiliation(s)
- Ruben Parra
- Department of Plant Physiology, Faculty of Science, University of Extremadura, Avda de Elvas s/n, 06006 Badajoz, Spain
| | - Miguel A Paredes
- Department of Plant Physiology, Faculty of Science, University of Extremadura, Avda de Elvas s/n, 06006 Badajoz, Spain
| | - Juana Labrador
- Department of Plant Physiology, Faculty of Science, University of Extremadura, Avda de Elvas s/n, 06006 Badajoz, Spain
| | - Cláudia Nunes
- Department of Chemistry, University of Aveiro, Aveiro P-3810-193, Portugal
| | - Manuel A Coimbra
- Department of Chemistry, University of Aveiro, Aveiro P-3810-193, Portugal
| | - Nieves Fernandez-Garcia
- Department of Abiotic Stress and Plant Pathology, Centro de Edafología y Biología Aplicada del Segura (CSIC), Murcia, Spain
| | - Enrique Olmos
- Department of Abiotic Stress and Plant Pathology, Centro de Edafología y Biología Aplicada del Segura (CSIC), Murcia, Spain
| | - Mercedes Gallardo
- Department of Plant Physiology, University of Vigo, Campus Lagoas-Marcosende, s/n, Vigo 36310, Spain
| | - Maria C Gomez-Jimenez
- Department of Plant Physiology, Faculty of Science, University of Extremadura, Avda de Elvas s/n, 06006 Badajoz, Spain
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13
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Li C, Ma X, Huang X, Wang H, Wu H, Zhao M, Li J. Involvement of HD-ZIP I transcription factors LcHB2 and LcHB3 in fruitlet abscission by promoting transcription of genes related to the biosynthesis of ethylene and ABA in litchi. TREE PHYSIOLOGY 2019; 39:1600-1613. [PMID: 31222320 DOI: 10.1093/treephys/tpz071] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 05/07/2019] [Accepted: 06/11/2019] [Indexed: 05/28/2023]
Abstract
Abnormal fruitlet abscission is a limiting factor in the production of litchi, an economically important fruit in Southern Asia. Both ethylene and abscisic acid (ABA) induce organ abscission in plants. Although ACS/ACO and NCED genes are known to encode key enzymes required for ethylene and ABA biosynthesis, respectively, the transcriptional regulation of these genes is unclear in the process of plant organ shedding. Here, two polygalacturonase (PG) genes (LcPG1 and LcPG2) and two novel homeodomain-leucine zipper I transcription factors genes (LcHB2 and LcHB3) were identified as key genes associated with the fruitlet abscission in litchi. The expression of LcPG1 and LcPG2 was strongly associated with litchi fruitlet abscission, consistent with enhanced PG activity and reduced homogalacturonan content in fruitlet abscission zones (FAZs). The promoter activities of LcPG1/2 were enhanced by ethephon and ABA. In addition, the production of ethylene and ABA in fruitlets was significantly increased during fruit abscission. Consistently, expression of five genes (LcACO2, LcACO3, LcACS1, LcACS4 and LcACS7) related to ethylene biosynthesis and one gene (LcNCED3) related to ABA biosynthesis in FAZs were activated. Further, electrophoretic mobility shift assays and transient expression experiments demonstrated that both LcHB2 and LcHB3 could directly bind to the promoter of LcACO2/3, LcACS1/4/7 and LcNCED3 genes and activate their expression. Collectively, we propose that LcHB2/3 are involved in the litchi fruitlet abscission through positive regulation of ethylene and ABA biosynthesis.
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Affiliation(s)
- Caiqin Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Xingshuai Ma
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Xuming Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Huicong Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Hong Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
| | - Minglei Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Jianguo Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
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14
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Fu X, Shi Z, Jiang Y, Jiang L, Qi M, Xu T, Li T. A family of auxin conjugate hydrolases from Solanum lycopersicum and analysis of their roles in flower pedicel abscission. BMC PLANT BIOLOGY 2019; 19:233. [PMID: 31159738 PMCID: PMC6547480 DOI: 10.1186/s12870-019-1840-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 05/20/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Auxin conjugates are hydrolyzed to release free auxin to ensure defined cellular auxin levels or gradients within tissues for proper development or response to environmental signals. The auxin concentration in the abscission zone (AZ) is thought to play an important role in mediating the abscission lag phase. RESULTS In this study, the full cDNA sequences of seven tomato ILR1-like SlILL genes were identified and characterized, All SlILLs were found to have auxin conjugate hydrolysis activity. The effects of different auxin conjugates on abscission identified IAA-Ile as a candidate to determine the auxin conjugate and auxin conjugate hydrolysis functions in abscission. Treatment of pedicel explants with IAA-Ile for different times showed that application before 6 h could effectively delay abscission. IAA-Ile pre-incubation for 2 h was sufficient to inhibit abscission. These results showed that there is not sufficient auxin conjugates in the AZ to inhibit abscission, and the optimal time to inhibit abscission by the application of exogenous auxin conjugates is before 6 h. Treatment with cycloheximide (CHX, a protein biosynthesis inhibitor) indicated that de novo synthesis of auxin conjugate hydrolases is also required to delay abscission. During abscission, SlILL1, 5, and 6 showed abscission-related gene expression patterns, and SlILL1, 3, 5, 6, and 7 showed increasing expression trends, which collectively might contribute to delay abscission. Silencing the expression of SlILL1, 3, 5, 6, and 7 using virus-induced gene silencing showed that SlILL1, 5, and 6 are major mediators of abscission in tomato. CONCLUSIONS In the process of abscission, auxin inhibition is concentration dependent, and the concentration of auxin in the AZ was regulated by hydrolyzed auxin conjugates. SlILR1, 5, and 6 play a key role in flower pedicel abscission.
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Affiliation(s)
- Xin Fu
- Horticulture Department, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
- Key Laboratory of Protected Horticulture of Ministry of Education, No.120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
| | - Zihang Shi
- Horticulture Department, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
- Key Laboratory of Protected Horticulture of Ministry of Education, No.120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
| | - Yun Jiang
- Horticulture Department, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
- Key Laboratory of Protected Horticulture of Ministry of Education, No.120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
| | - Lingling Jiang
- Shenyang Entry-exit Inspection and Quarantine Bureau, No.433 Danan street, Shenhe District, Shenyang, 110016, Liaoning, China
| | - Mingfang Qi
- Horticulture Department, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
- Key Laboratory of Protected Horticulture of Ministry of Education, No.120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China
| | - Tao Xu
- Horticulture Department, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China.
- Key Laboratory of Protected Horticulture of Ministry of Education, No.120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China.
| | - Tianlai Li
- Horticulture Department, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China.
- Key Laboratory of Protected Horticulture of Ministry of Education, No.120 Dongling Road, Shenhe District, Shenyang, 110866, Liaoning, China.
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15
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Meir S, Philosoph-Hadas S, Riov J, Tucker ML, Patterson SE, Roberts JA. Re-evaluation of the ethylene-dependent and -independent pathways in the regulation of floral and organ abscission. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1461-1467. [PMID: 30726930 DOI: 10.1093/jxb/erz038] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 01/15/2019] [Indexed: 05/25/2023]
Abstract
Abscission is a developmental process with important implications for agricultural practices. Ethylene has long been considered as a key regulator of the abscission process. The existence of an ethylene-independent abscission pathway, controlled by the complex of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) peptide and the HAESA (HAE) and HAESA-like2 (HSL2) kinases, has been proposed, based mainly on observations that organ abscission in ethylene-insensitive mutants was delayed but not inhibited. A recent review on plant organ abscission signaling highlighted the IDA-HAE-HSL2 components as the regulators of organ abscission, while the role of auxin and ethylene in this process was hardly addressed. After a careful analysis of the relevant abscission literature, we propose that the IDA-HAE-HSL2 pathway is essential for the final stages of organ abscission, while ethylene plays a major role in its initiation and progression. We discuss the view that the IDA-HAE-HSL2 pathway is ethylene independent, and present recent evidence showing that ethylene activates the IDA-HAE-HSL2 complex. We conclude that the ability of an organ to abscise is tightly linked to cell turgidity in the abscission zone, and suggest that lack of cell turgidity might contribute to the failure of floral organ abscission in the ida mutants.
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Affiliation(s)
- Shimon Meir
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZion, Israel
| | - Sonia Philosoph-Hadas
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZion, Israel
| | - Joseph Riov
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Mark L Tucker
- Soybean Genomics and Improvement Lab, Agricultural Research Service, United States Department of Agriculture, BARC-West, Beltsville, MD, USA
| | - Sara E Patterson
- Department of Horticulture, University of Wisconsin-Madison, Madison, WI, USA
| | - Jeremy A Roberts
- Office of the Vice-Chancellor, Drake Circus, Plymouth, Devon, UK
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16
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Cheng Q, Bai S, Ge G, Li P, Liu L, Zhang C, Jia Y. Study on differentially expressed genes related to defoliation traits in two alfalfa varieties based on RNA-Seq. BMC Genomics 2018; 19:807. [PMID: 30404602 PMCID: PMC6223052 DOI: 10.1186/s12864-018-5180-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 10/17/2018] [Indexed: 01/15/2023] Open
Abstract
Background Alfalfa (Medicago sativa) is a widely cultivated, essential commercial forage crop. The protein content in its leaves is the critical factor in determining the quality of alfalfa. Thus far, the understanding of the molecular mechanism of alfalfa defoliation traits remains unclear. The transcriptome database created by RNA-Seq is used to identify critical genes related to defoliation traits. Results In this study, we sequenced the transcriptomes of the Zhungeer variety (with easy leaf abscission) and WL319HQ variety (without easy leaf abscission). Among the identified 66,734 unigenes, 706 differentially expressed genes (DEGs) upregulated, and 392 unigenes downregulated in the Zhungeer vs WL319HQ leaf. KEGG pathway annotations showed that 8,414 unigenes were annotated to 87 pathways and contained 281 DEGs. Six DEGs belonging to the “Carotenoid biosynthesis”, “Plant hormone signal transduction” and “Circadian rhythm-plant” pathways involved in defoliation traits were identified and validated by RT-qPCR analyses. Conclusions This study used RNA-Seq to discover genes associated with defoliation traits between two alfalfa varieties. Our transcriptome data dramatically enriches alfalfa functional genomic studies. In addition, these data provide theoretical guidance for field production practice and genetic breeding, as well as references for future study of defoliation traits in alfalfa. Electronic supplementary material The online version of this article (10.1186/s12864-018-5180-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Qiming Cheng
- College of Grassland Resources and Environment, Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of the Ministry of Agriculture and Key Laboratory of Grassland Resources of the Ministry of Education, Inner Mongolia Agricultural University, Hohhot, 010011, China
| | - Shiqie Bai
- Sichuan Academy of Grassland Sciences, Chengdu, 611731, China
| | - Gentu Ge
- College of Grassland Resources and Environment, Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of the Ministry of Agriculture and Key Laboratory of Grassland Resources of the Ministry of Education, Inner Mongolia Agricultural University, Hohhot, 010011, China
| | - Ping Li
- Sichuan Academy of Grassland Sciences, Chengdu, 611731, China
| | - Liying Liu
- Inner Mongolia Academy of Forestry Science, Hohhot, 010010, China
| | - Chengdong Zhang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Randwick, NSW, 2052, Australia.
| | - Yushan Jia
- College of Grassland Resources and Environment, Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of the Ministry of Agriculture and Key Laboratory of Grassland Resources of the Ministry of Education, Inner Mongolia Agricultural University, Hohhot, 010011, China.
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17
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Qi X, Hu S, Zhou H, Liu X, Wang L, Zhao B, Huang X, Zhang S. A MADS-box transcription factor of 'Kuerlexiangli'(Pyrus sinkiangensis Yu) PsJOINTLESS gene functions in floral organ abscission. Gene 2018; 642:163-171. [PMID: 29128637 DOI: 10.1016/j.gene.2017.11.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/25/2017] [Accepted: 11/07/2017] [Indexed: 10/18/2022]
Abstract
MADS-box proteins have been implicated in many biological processes. However, plant MADS-box proteins functioning in floral organ abscission and the underlying physiological mechanisms remain poorly understood. Here, we report the identification and functional characterization of PsJOINTLESS isolated from 'Kuerlexiangli'. PsJOINTLESS had a complete open reading frame of 672bp, encoding a 224 amino acid peptide, and shared high sequence identities with MADS-box from other plants. PsJOINTLESS was subcellularly targeted to the nucleus, supporting its role as a transcription factor. Expression levels of PsJOINTLESS in the calyx tube were strongly induced by calyx abscission treatment at 6d after full bloom. Overexpression of PsJOINTLESS in tomato enhanced the rate of pedicel abscission rate. Of special note, the transgenic plants increased the abscission zone cell layer compared with wild type. Furthermore, the tomato transgenic lines showed thinner flower pedicels, more cell number and small pedicel cell size. The cellulase activity in pedicel abscission zone of transgenic plants was higher than that of wild type. In addition, steady-state mRNA levels of five cell wall hydrolase genes coding for either functional or regulatory proteins were induced to higher levels in the transgenic lines. These results clearly demonstrate that PsJOINTLESS may affect pedicel abscission zone development.
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Affiliation(s)
- Xiaoxiao Qi
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China; College of Agriculture, Medicine and Health, Anhui Radio and Television University, China
| | - Shi Hu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Hongsheng Zhou
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Xing Liu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Lifen Wang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Biying Zhao
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaosan Huang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
| | - Shaoling Zhang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
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18
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Sundaresan S, Philosoph-Hadas S, Ma C, Jiang CZ, Riov J, Mugasimangalam R, Kochanek B, Salim S, Reid MS, Meir S. The Tomato Hybrid Proline-rich Protein regulates the abscission zone competence to respond to ethylene signals. HORTICULTURE RESEARCH 2018; 5:28. [PMID: 29872533 PMCID: PMC5981600 DOI: 10.1038/s41438-018-0033-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 05/04/2023]
Abstract
The Tomato Hybrid Proline-rich Protein (THyPRP) gene was specifically expressed in the tomato (Solanum lycopersicum) flower abscission zone (FAZ), and its stable antisense silencing under the control of an abscission zone (AZ)-specific promoter, Tomato Abscission Polygalacturonase4, significantly inhibited tomato pedicel abscission following flower removal. For understanding the THyPRP role in regulating pedicel abscission, a transcriptomic analysis of the FAZ of THyPRP-silenced plants was performed, using a newly developed AZ-specific tomato microarray chip. Decreased expression of THyPRP in the silenced plants was already observed before abscission induction, resulting in FAZ-specific altered gene expression of transcription factors, epigenetic modifiers, post-translational regulators, and transporters. Our data demonstrate that the effect of THyPRP silencing on pedicel abscission was not mediated by its effect on auxin balance, but by decreased ethylene biosynthesis and response. Additionally, THyPRP silencing revealed new players, which were demonstrated for the first time to be involved in regulating pedicel abscission processes. These include: gibberellin perception, Ca2+-Calmodulin signaling, Serpins and Small Ubiquitin-related Modifier proteins involved in post-translational modifications, Synthaxin and SNARE-like proteins, which participate in exocytosis, a process necessary for cell separation. These changes, occurring in the silenced plants early after flower removal, inhibited and/or delayed the acquisition of the competence of the FAZ cells to respond to ethylene signaling. Our results suggest that THyPRP acts as a master regulator of flower abscission in tomato, predominantly by playing a role in the regulation of the FAZ cell competence to respond to ethylene signals.
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Affiliation(s)
- Srivignesh Sundaresan
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZiyon, Israel
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
- Present Address: Department of Nano Science and Technology, Tamil Nadu Agricultural University, Coimbatore, India
| | - Sonia Philosoph-Hadas
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZiyon, Israel
| | - Chao Ma
- Department of Plant Sciences, University of California, Davis, CA USA
- Present Address: Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, China
| | - Cai-Zhong Jiang
- Department of Plant Sciences, University of California, Davis, CA USA
- Crops Pathology & Genetic Research Unit, USDA-ARS, Davis, CA USA
| | - Joseph Riov
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Raja Mugasimangalam
- Department of Bioinformatics, QTLomics Technologies Pvt. Ltd, Bangalore, India
| | - Betina Kochanek
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZiyon, Israel
| | - Shoshana Salim
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZiyon, Israel
| | - Michael S. Reid
- Department of Plant Sciences, University of California, Davis, CA USA
| | - Shimon Meir
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZiyon, Israel
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19
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Wilmowicz E, Frankowski K, Kućko A, Świdziński M, de Dios Alché J, Nowakowska A, Kopcewicz J. The influence of abscisic acid on the ethylene biosynthesis pathway in the functioning of the flower abscission zone in Lupinus luteus. JOURNAL OF PLANT PHYSIOLOGY 2016; 206:49-58. [PMID: 27689739 DOI: 10.1016/j.jplph.2016.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 08/12/2016] [Accepted: 08/12/2016] [Indexed: 05/03/2023]
Abstract
Flower abscission is a highly regulated developmental process activated in response to exogenous (e.g. changing environmental conditions) and endogenous stimuli (e.g. phytohormones). Ethylene (ET) and abscisic acid (ABA) are very effective stimulators of flower abortion in Lupinus luteus, which is a widely cultivated species in Poland, Australia and Mediterranean countries. In this paper, we show that artificial activation of abscission by flower removal caused an accumulation of ABA in the abscission zone (AZ). Moreover, the blocking of that phytohormone's biosynthesis by NDGA (nordihydroguaiaretic acid) decreased the number of abscised flowers. However, the application of NBD - an inhibitor of ET action - reversed the stimulatory effect of ABA on flower abscission, indicating that ABA itself is not sufficient to turn on the organ separation. Our analysis revealed that exogenous ABA significantly accelerated the transcriptional activity of the ET biosynthesis genes ACC synthase (LlACS) and oxidase (LlACO), and moreover, strongly increased the level of 1-aminocyclopropane-1-carboxylic acid (ACC) - ET precursor, which was specifically localized within AZ cells. We cannot exclude the possibility that ABA mediates flower abscission processes by enhancing the ET biosynthesis rate. The findings of our study will contribute to the overall basic knowledge on the phytohormone-regulated generative organs abscission in L. luteus.
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Affiliation(s)
- Emilia Wilmowicz
- Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland; Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 4 Wileńska Street, 87-100 Toruń, Poland.
| | - Kamil Frankowski
- Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland.
| | - Agata Kućko
- Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland.
| | - Michał Świdziński
- Department of Cell Biology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland.
| | - Juan de Dios Alché
- Department of Biochemistry, Cellular and Molecular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008, Granada, Spain.
| | - Anna Nowakowska
- Department of Animal Physiology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland.
| | - Jan Kopcewicz
- Chair of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Toruń, Poland.
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20
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Patterson SE, Bolivar-Medina JL, Falbel TG, Hedtcke JL, Nevarez-McBride D, Maule AF, Zalapa JE. Are We on the Right Track: Can Our Understanding of Abscission in Model Systems Promote or Derail Making Improvements in Less Studied Crops? FRONTIERS IN PLANT SCIENCE 2016; 6:1268. [PMID: 26858730 PMCID: PMC4726918 DOI: 10.3389/fpls.2015.01268] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/28/2015] [Indexed: 05/24/2023]
Abstract
As the world population grows and resources and climate conditions change, crop improvement continues to be one of the most important challenges for agriculturalists. The yield and quality of many crops is affected by abscission or shattering, and environmental stresses often hasten or alter the abscission process. Understanding this process can not only lead to genetic improvement, but also changes in cultural practices and management that will contribute to higher yields, improved quality and greater sustainability. As plant scientists, we have learned significant amounts about this process through the study of model plants such as Arabidopsis, tomato, rice, and maize. While these model systems have provided significant valuable information, we are sometimes challenged to use this knowledge effectively as variables including the economic value of the crop, the uniformity of the crop, ploidy levels, flowering and crossing mechanisms, ethylene responses, cultural requirements, responses to changes in environment, and cellular and tissue specific morphological differences can significantly influence outcomes. The value of genomic resources for lesser-studied crops such as cranberries and grapes and the orphan crop fonio will also be considered.
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Affiliation(s)
- Sara E. Patterson
- Department of Horticulture, University of Wisconsin–MadisonMadison, WI, USA
| | - Jenny L. Bolivar-Medina
- Department of Horticulture, University of Wisconsin–MadisonMadison, WI, USA
- Vegetable Crops Research Unit, United States Department of Agriculture – Agricultural Research ServiceMadison, WI, USA
| | - Tanya G. Falbel
- Department of Horticulture, University of Wisconsin–MadisonMadison, WI, USA
| | | | | | - Andrew F. Maule
- Department of Horticulture, University of Wisconsin–MadisonMadison, WI, USA
| | - Juan E. Zalapa
- Department of Horticulture, University of Wisconsin–MadisonMadison, WI, USA
- Vegetable Crops Research Unit, United States Department of Agriculture – Agricultural Research ServiceMadison, WI, USA
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21
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Butenko MA, Simon R. Beyond the meristems: similarities in the CLAVATA3 and INFLORESCENCE DEFICIENT IN ABSCISSION peptide mediated signalling pathways. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:5195-203. [PMID: 26105996 DOI: 10.1093/jxb/erv310] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Plants form new organs throughout their lives; this requires a balance between cell proliferation and differentiation, and between the generation and loss of organs. To do this, plants must maintain a population of stem cells within the meristems, and at the same time, closely control the identity and position of cells at the meristem boundaries as they differentiate to new leaf or flower primordia. Once developed, organs may need to be shed, either as a controlled developmental decision-such as floral abscission after pollination, or as a response to disease, environmental stress, and predators. Cell wall degradation at specialized abscission zone (AZ) cells needs to occur for this to take place, but since there is little cell rearrangement in plants, cell separation events are also important for plant architecture. In this Opinion paper we discuss the role of two peptide ligand signalling systems that control stem cell homeostasis and cell separation, respectively. We draw parallels between the signalling pathways and explore on the commonalities of the downstream components activated and controlled by the signalling peptides. We provide evidence for AZ cells having a meristem identity and discuss the role of identical KNOTTED-LIKE HOMEOBOX (KNOX) transcription factors in meristem maintenance and abscission. Lastly we explore the evolutionary relationship between the pathways.
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Affiliation(s)
- Melinka A Butenko
- Department of Biosciences, Section for Genetics and Evolutionary Biology, University of Oslo, 0316 Oslo, Norway
| | - Rüdiger Simon
- Institute for Developmental Genetics and Cluster of Excellence on Plant Sciences (CEPLAS), Universitätsstr. 1, Heinrich-Heine University, 40225 Düsseldorf, Germany
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22
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Cheng C, Zhang L, Yang X, Zhong G. Profiling gene expression in citrus fruit calyx abscission zone (AZ-C) treated with ethylene. Mol Genet Genomics 2015; 290:1991-2006. [PMID: 25948248 DOI: 10.1007/s00438-015-1054-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 04/20/2015] [Indexed: 02/06/2023]
Abstract
On-tree storage and harvesting of mature fruit account for a large proportion of cost in the production of citrus, and a reduction of the cost would not be achieved without a thorough understanding of the mechani sm of the mature fruit abscission. Genome-wide gene expression changes in ethylene-treated fruit calyx abscission zone (AZ-C) of Citrus sinensis cv. Olinda were therefore investigated using a citrus genome array representing up to 33,879 citrus transcripts. In total, 1313 and 1044 differentially regulated genes were identified in AZ-C treated with ethylene for 4 and 24 h, respectively. The results showed that mature citrus fruit abscission commenced with the activation of ethylene signal transduction pathway that led to the activation of ethylene responsive transcription factors and the subsequent transcriptional regulation of a large set of ethylene responsive genes. Significantly down-regulated genes included those of starch/sugar biosynthesis, transportation of water and growth promoting hormone synthesis and signaling, whereas significantly up-regulated genes were those involved in defense, cell wall degradation, and secondary metabolism. Our data unraveled the underlying mechanisms of some known important biochemical events occurring at AZ-C and should provide informative suggestions for future manipulation of the events to achieve a controllable abscission for mature citrus fruit.
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Affiliation(s)
- Chunzhen Cheng
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences Guangzhou, Guangdong, 510640, People's Republic of China. .,College of Horticulture and Landscape Architecture, Southwest University, Beibei, Chongqing, 400715, People's Republic of China. .,Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization Ministry of Agriculture Guangzhou, Guangdong, 510640, People's Republic of China. .,Key Laboratory of Tropical and Subtropical Fruit tree Researches, Guangdong Province Guangzhou, Guangdong, 510640, People's Republic of China.
| | - Lingyun Zhang
- School of Geographic and Environmental Sciences, Guizhou Normal University Guizhou, Guiyang, 550001, People's Republic of China
| | - Xuelian Yang
- College of Agriculture, Guizhou University Guiyang, Guizhou, 550025, People's Republic of China
| | - Guangyan Zhong
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences Guangzhou, Guangdong, 510640, People's Republic of China. .,Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization Ministry of Agriculture Guangzhou, Guangdong, 510640, People's Republic of China. .,Key Laboratory of Tropical and Subtropical Fruit tree Researches, Guangdong Province Guangzhou, Guangdong, 510640, People's Republic of China.
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23
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Sawicki M, Aït Barka E, Clément C, Vaillant-Gaveau N, Jacquard C. Cross-talk between environmental stresses and plant metabolism during reproductive organ abscission. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1707-19. [PMID: 25711702 PMCID: PMC4669552 DOI: 10.1093/jxb/eru533] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/04/2014] [Accepted: 12/09/2014] [Indexed: 05/06/2023]
Abstract
In plants, flowering is a crucial process for reproductive success and continuity of the species through time. Fruit production requires the perfect development of reproductive structures. Abscission, a natural process, can occur to facilitate shedding of no longer needed, infected, or damaged organs. If stress occurs during flower development, abscission can intervene at flower level, leading to reduced yield. Flower abscission is a highly regulated developmental process simultaneously influenced and activated in response to exogenous (changing environmental conditions, interactions with microorganisms) and endogenous (physiological modifications) stimuli. During climate change, plant communities will be more susceptible to environmental stresses, leading to increased flower and fruit abscission, and consequently a decrease in fruit yield. Understanding the impacts of stress on the reproductive phase is therefore critical for managing future agricultural productivity. Here, current knowledge on flower/fruit abscission is summarized by focusing specifically on effects of environmental stresses leading to this process in woody plants. Many of these stresses impair hormonal balance and/or carbohydrate metabolism, but the exact mechanisms are far from completely known. Hormones are the abscission effectors and the auxin/ethylene balance is of particular importance. The carbohydrate pathway is the result of complex regulatory processes involving the balance between photosynthesis and mobilization of reserves. Hormones and carbohydrates together participate in complex signal transduction systems, especially in response to stress. The available data are discussed in relation to reproductive organ development and the process of abscission.
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Affiliation(s)
- Mélodie Sawicki
- Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Unité de Recherche Vignes et Vins de Champagne - EA 4707, Moulin de la Housse - Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France
| | - Essaïd Aït Barka
- Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Unité de Recherche Vignes et Vins de Champagne - EA 4707, Moulin de la Housse - Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France
| | - Christophe Clément
- Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Unité de Recherche Vignes et Vins de Champagne - EA 4707, Moulin de la Housse - Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France
| | - Nathalie Vaillant-Gaveau
- Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Unité de Recherche Vignes et Vins de Champagne - EA 4707, Moulin de la Housse - Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France
| | - Cédric Jacquard
- Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Unité de Recherche Vignes et Vins de Champagne - EA 4707, Moulin de la Housse - Bâtiment 18, BP 1039, 51687 Reims Cedex 2, France
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24
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Sundaresan S, Philosoph-Hadas S, Riov J, Belausov E, Kochanek B, Tucker ML, Meir S. Abscission of flowers and floral organs is closely associated with alkalization of the cytosol in abscission zone cells. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1355-68. [PMID: 25504336 PMCID: PMC4339595 DOI: 10.1093/jxb/eru483] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In vivo changes in the cytosolic pH of abscission zone (AZ) cells were visualized using confocal microscopic detection of the fluorescent pH-sensitive and intracellularly trapped dye, 2',7'-bis-(2-carboxyethyl)-5(and-6)-carboxyfluorescein (BCECF), driven by its acetoxymethyl ester. A specific and gradual increase in the cytosolic pH of AZ cells was observed during natural abscission of flower organs in Arabidopsis thaliana and wild rocket (Diplotaxis tenuifolia), and during flower pedicel abscission induced by flower removal in tomato (Solanum lycopersicum Mill). The alkalization pattern in the first two species paralleled the acceleration or inhibition of flower organ abscission induced by ethylene or its inhibitor 1-methylcyclopropene (1-MCP), respectively. Similarly, 1-MCP pre-treatment of tomato inflorescence explants abolished the pH increase in AZ cells and pedicel abscission induced by flower removal. Examination of the pH changes in the AZ cells of Arabidopsis mutants defective in both ethylene-induced (ctr1, ein2, eto4) and ethylene-independent (ida, nev7, dab5) abscission pathways confirmed these results. The data indicate that the pH changes in the AZ cells are part of both the ethylene-sensitive and -insensitive abscission pathways, and occur concomitantly with the execution of organ abscission. pH can affect enzymatic activities and/or act as a signal for gene expression. Changes in pH during abscission could occur via regulation of transporters in AZ cells, which might affect cytosolic pH. Indeed, four genes associated with pH regulation, vacuolar H(+)-ATPase, putative high-affinity nitrate transporter, and two GTP-binding proteins, were specifically up-regulated in tomato flower AZ following abscission induction, and 1-MCP reduced or abolished the increased expression.
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Affiliation(s)
- Srivignesh Sundaresan
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Bet-Dagan 5025001, Israel The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Sonia Philosoph-Hadas
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Bet-Dagan 5025001, Israel
| | - Joseph Riov
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Eduard Belausov
- Department of Ornamental Horticulture, Agricultural Research Organization (ARO), The Volcani Center, Bet-Dagan 5025001, Israel
| | - Betina Kochanek
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Bet-Dagan 5025001, Israel
| | - Mark L Tucker
- Soybean Genomics and Improvement Laboratory, USDA-ARS, Beltsville, MD 20705, USA
| | - Shimon Meir
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Bet-Dagan 5025001, Israel
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25
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Lombardi L, Arrom L, Mariotti L, Battelli R, Picciarelli P, Kille P, Stead T, Munné-Bosch S, Rogers HJ. Auxin involvement in tepal senescence and abscission in Lilium: a tale of two lilies. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:945-56. [PMID: 25422499 PMCID: PMC4321550 DOI: 10.1093/jxb/eru451] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Petal wilting and/or abscission terminates the life of the flower. However, how wilting and abscission are coordinated is not fully understood. There is wide variation in the extent to which petals wilt before abscission, even between cultivars of the same species. For example, tepals of Lilium longiflorum wilt substantially, while those of the closely related Lilium longiflorum×Asiatic hybrid (L.A.) abscise turgid. Furthermore, close comparison of petal death in these two Lilium genotypes shows that there is a dramatic fall in fresh weight/dry weight accompanied by a sharp increase in ion leakage in late senescent L. longiflorum tepals, neither of which occur in Lilium L.A. Despite these differences, a putative abscission zone was identified in both lilies, but while the detachment force was reduced to zero in Lilium L.A., wilting of the fused tepals in L. longiflorum occurred before abscission was complete. Abscission is often negatively regulated by auxin, and the possible role of auxin in regulating tepal abscission relative to wilting was tested in the two lilies. There was a dramatic increase in auxin levels with senescence in L. longiflorum but not in Lilium L.A. Fifty auxin-related genes were expressed in early senescent L. longiflorum tepals including 12 ARF-related genes. In Arabidopsis, several ARF genes are involved in the regulation of abscission. Expression of a homologous transcript to Arabidopsis ARF7/19 was 8-fold higher during senescence in L. longiflorum compared with abscising Lilium L.A., suggesting a conserved role for auxin-regulated abscission in monocotyledonous ethylene-insensitive flowers.
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Affiliation(s)
- Lara Lombardi
- Department of Biology, University of Pisa, Via Ghini 5, 56126 Pisa, Italy
| | - Laia Arrom
- Department of Plant Biology, Faculty of Biology, University of Barcelona, Avinguda Diagonal, 645, 08028 Barcelona, Spain School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Lorenzo Mariotti
- Department of Biology, University of Pisa, Via Ghini 5, 56126 Pisa, Italy
| | - Riccardo Battelli
- Department of Agriculture, Food and Environment, University of Pisa, Via Mariscoglio 34, 56124 Pisa, Italy
| | - Piero Picciarelli
- Department of Agriculture, Food and Environment, University of Pisa, Via Mariscoglio 34, 56124 Pisa, Italy
| | - Peter Kille
- School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Tony Stead
- School of Biological Sciences, Royal Holloway, University of London, Egham Hill, Egham, Surrey TW20 0EX, UK
| | - Sergi Munné-Bosch
- Department of Plant Biology, Faculty of Biology, University of Barcelona, Avinguda Diagonal, 645, 08028 Barcelona, Spain
| | - Hilary J Rogers
- School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
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26
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Sundaresan S, Philosoph-Hadas S, Riov J, Mugasimangalam R, Kuravadi NA, Kochanek B, Salim S, Tucker ML, Meir S. De novo Transcriptome Sequencing and Development of Abscission Zone-Specific Microarray as a New Molecular Tool for Analysis of Tomato Organ Abscission. FRONTIERS IN PLANT SCIENCE 2015; 6:1258. [PMID: 26834766 PMCID: PMC4712312 DOI: 10.3389/fpls.2015.01258] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/24/2015] [Indexed: 05/19/2023]
Abstract
Abscission of flower pedicels and leaf petioles of tomato (Solanum lycopersicum) can be induced by flower removal or leaf deblading, respectively, which leads to auxin depletion, resulting in increased sensitivity of the abscission zone (AZ) to ethylene. However, the molecular mechanisms that drive the acquisition of abscission competence and its modulation by auxin gradients are not yet known. We used RNA-Sequencing (RNA-Seq) to obtain a comprehensive transcriptome of tomato flower AZ (FAZ) and leaf AZ (LAZ) during abscission. RNA-Seq was performed on a pool of total RNA extracted from tomato FAZ and LAZ, at different abscission stages, followed by de novo assembly. The assembled clusters contained transcripts that are already known in the Solanaceae (SOL) genomics and NCBI databases, and over 8823 identified novel tomato transcripts of varying sizes. An AZ-specific microarray, encompassing the novel transcripts identified in this study and all known transcripts from the SOL genomics and NCBI databases, was constructed to study the abscission process. Multiple probes for longer genes and key AZ-specific genes, including antisense probes for all transcripts, make this array a unique tool for studying abscission with a comprehensive set of transcripts, and for mining for naturally occurring antisense transcripts. We focused on comparing the global transcriptomes generated from the FAZ and the LAZ to establish the divergences and similarities in their transcriptional networks, and particularly to characterize the processes and transcriptional regulators enriched in gene clusters that are differentially regulated in these two AZs. This study is the first attempt to analyze the global gene expression in different AZs in tomato by combining the RNA-Seq technique with oligonucleotide microarrays. Our AZ-specific microarray chip provides a cost-effective approach for expression profiling and robust analysis of multiple samples in a rapid succession.
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Affiliation(s)
- Srivignesh Sundaresan
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani CenterBet-Dagan, Israel
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of JerusalemRehovot, Israel
| | - Sonia Philosoph-Hadas
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani CenterBet-Dagan, Israel
| | - Joseph Riov
- The Robert H. Smith Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of JerusalemRehovot, Israel
| | - Raja Mugasimangalam
- Department of Bioinformatics, QTLomics Technologies Pvt. LtdBangalore, India
| | - Nagesh A. Kuravadi
- Department of Bioinformatics, QTLomics Technologies Pvt. LtdBangalore, India
| | - Bettina Kochanek
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani CenterBet-Dagan, Israel
| | - Shoshana Salim
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani CenterBet-Dagan, Israel
| | - Mark L. Tucker
- Soybean Genomics and Improvement Laboratory, United States Department of Agriculture, Agricultural Research ServiceBeltsville, MD, USA
| | - Shimon Meir
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani CenterBet-Dagan, Israel
- *Correspondence: Shimon Meir
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Hvoslef-Eide AK, Munster CM, Mathiesen CA, Ayeh KO, Melby TI, Rasolomanana P, Lee Y. Primary and Secondary Abscission in Pisum sativum and Euphorbia pulcherrima-How Do They Compare and How Do They Differ? FRONTIERS IN PLANT SCIENCE 2015; 6:1204. [PMID: 26858724 PMCID: PMC4726753 DOI: 10.3389/fpls.2015.01204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/14/2015] [Indexed: 05/04/2023]
Abstract
Abscission is a highly regulated and coordinated developmental process in plants. It is important to understand the processes leading up to the event, in order to better control abscission in crop plants. This has the potential to reduce yield losses in the field and increase the ornamental value of flowers and potted plants. A reliable method of abscission induction in poinsettia (Euphorbia pulcherrima) flowers has been established to study the process in a comprehensive manner. By correctly decapitating buds of the third order, abscission can be induced in 1 week. AFLP differential display (DD) was used to search for genes regulating abscission. Through validation using qRT-PCR, more information of the genes involved during induced secondary abscission have been obtained. A study using two pea (Pisum sativum) mutants in the def (Developmental funiculus) gene, which was compared with wild type peas (tall and dwarf in both cases) was performed. The def mutant results in a deformed, abscission-less zone instead of normal primary abscission at the funiculus. RNA in situ hybridization studies using gene sequences from the poinsettia differential display, resulted in six genes differentially expressed for abscission specific genes in both poinsettia and pea. Two of these genes are associated with gene up- or down-regulation during the first 2 days after decapitation in poinsettia. Present and previous results in poinsettia (biochemically and gene expressions), enables a more detailed division of the secondary abscission phases in poinsettia than what has previously been described from primary abscission in Arabidopsis. This study compares the inducible secondary abscission in poinsettia and the non-abscising mutants/wild types in pea demonstrating primary abscission zones. The results may have wide implications on the understanding of abscission, since pea and poinsettia have been separated for 94-98 million years in evolution, hence any genes or processes in common are bound to be widespread in the plant kingdom.
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Estornell LH, Wildhagen M, Pérez-Amador MA, Talón M, Tadeo FR, Butenko MA. The IDA Peptide Controls Abscission in Arabidopsis and Citrus. FRONTIERS IN PLANT SCIENCE 2015; 6:1003. [PMID: 26635830 PMCID: PMC4652038 DOI: 10.3389/fpls.2015.01003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/30/2015] [Indexed: 05/22/2023]
Abstract
Organ abscission is an important process in plant development and reproduction. During abscission, changes in cellular adhesion of specialized abscission zone cells ensure the detachment of infected organs or those no longer serving a function to the plant. In addition, abscission also plays an important role in the release of ripe fruits. Different plant species display distinct patterns and timing of organ shedding, most likely adapted during evolution to their diverse life styles. However, it appears that key regulators of cell separation may have conserved function in different plant species. Here, we investigate the functional conservation of the citrus ortholog of the Arabidopsis peptide ligand INFLORESCENCE DEFICIENT IN ABSCISSION (AtIDA), controlling floral organ abscission. We discuss the possible implications of modifying the citrus IDA ortholog for citrus fruit production.
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Affiliation(s)
| | - Mari Wildhagen
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of OsloOslo, Norway
| | - Miguel A. Pérez-Amador
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia–Consejo Superior de Investigaciones CientíficasValència, Spain
| | - Manuel Talón
- Centre de Genómica, Institut Valencià d’Investigacions AgràriesMontcada, Spain
| | - Francisco R. Tadeo
- Centre de Genómica, Institut Valencià d’Investigacions AgràriesMontcada, Spain
- *Correspondence: Franscisco R. Tadeo, ; Melinka A. Butenko,
| | - Melinka A. Butenko
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of OsloOslo, Norway
- *Correspondence: Franscisco R. Tadeo, ; Melinka A. Butenko,
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Kim J. Four shades of detachment: regulation of floral organ abscission. PLANT SIGNALING & BEHAVIOR 2014; 9:e976154. [PMID: 25482787 PMCID: PMC4623469 DOI: 10.4161/15592324.2014.976154] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/15/2014] [Accepted: 08/15/2014] [Indexed: 05/19/2023]
Abstract
Abscission of floral organs from the main body of a plant is a dynamic process that is developmentally and environmentally regulated. In the past decade, genetic studies in Arabidopsis have identified key signaling components and revealed their interactions in the regulation of floral organ abscission. The phytohormones jasmonic acid (JA) and ethylene play critical roles in flower development and floral organ abscission. These hormones regulate the timing of floral organ abscission both independently and inter-dependently. Although significant progress has been made in understanding abscission signaling, there are still many unanswered questions. These include considering abscission in the context of reproductive development and interplay between hormones embedded in the developmental processes. This review summarizes recent advances in the identification of molecular components in Arabidopsis and discusses their relationship with reproductive development. The emerging roles of hormones in the regulation of floral organ abscission, particularly by JA and ethylene, are examined.
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Key Words
- AGL15, AGAMOUS-LIKE 15
- AOS/DDE2, ALLENE OXIDE SYNTHASE/DELAYED DEHISCENCE 2
- ARF-GAP, ADP-ribosylation factor-GTPase activating protein
- AZ, abscission zone
- BOP1/2, BLADE ON PETIOLE 1/2
- BTP/POZ, Broad-Complex, Tramtrack, and Bric-a-brac/Pox virus and Zinc finger
- CST, CAST AWAY RECEPTOR-LIKE KINASE
- CTR1, CONSTITUTIVE TRIPLE RESPONSE 1
- DAB4/ COI1, DELAYED ABSCISSION 4/CORONATINE INSENSITIVE 1
- DAD1, DEFECTIVE ANTHER DEHISCENCE 1
- DDE1/OPR3, DELAYED DEHISCENCE 1/OXOPHYTODIENOATE-REDUCTASE 3
- EVR, EVERSHED RECEPTOR-LIKE KINASE
- EXP, EXPANSIN
- FAD7/8/3, FATTY ACID DESATURASE 7/8/3
- FYF, FOREVER YOUNG FLOWER
- HAE/HSL2, HAESA/HAESA-LIKE 2
- IM, inflorescence meristem
- JA, jasmonic acid
- JAZ, JASMONATE-ZIM DOMAIN
- KNAT1, KNOTTED-LIKE FROM ARABIDOPSIS THALIANA 1
- LOX3/4, LIPOXYGENASE 3/4
- LRR, leucine-rich repeat
- MAPK3/6, MAP Kinase 3/6
- MKK4/5, MAP Kinase Kinase 4/5
- NEV, NEVERSHED
- NPR1, NONEXPRESSOR OF PR GENES 1
- PG , POLYGALATURONASE
- PR1, Pathogenesis-related Protein 1
- SERK1, SOMATIC EMBRYO RECEPTOR-LIKE KIASE 1
- TCP4, TEOSINTE BRANCHED/CYCLOIDEA/PCF4
- XTH , XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE
- ein2-1, ethylene insensitive 2-1
- ethylene
- etr1-1, ethylene response1-1
- floral organ abscission
- flower senescence
- ida, inflorescence deficient in abscission
- inflorescence meristem
- jasmonic acid
- reproductive development
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Affiliation(s)
- Joonyup Kim
- Soybean Genomics and Improvement Laboratory; Agricultural Research Service; USDA; Beltsville, MD USA
- Correspondence to: Joonyup Kim;
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Aalen RB, Wildhagen M, Stø IM, Butenko MA. IDA: a peptide ligand regulating cell separation processes in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:5253-61. [PMID: 24151306 DOI: 10.1093/jxb/ert338] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In contrast to animals, plants continuously produce new organs, such as leaves, flowers, and lateral roots (LRs), and may shed organs that have served their purpose. In the model plant Arabidopsis thaliana the peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) signals through the leucine-rich repeat-receptor-like kinases (LRR-RLKs) HAESA (HAE), and HAESA-LIKE2 (HSL2) to control the abscission of floral organs after pollination. Recent work from other plant species indicates that this signalling system is conserved and could regulate leaf abscission in soybean and tomato. Abscission is a cell separation process involving the breakdown of cell walls between adjacent files of abscission zone (AZ) cells at the base of organs to be shed. The emergence of new lateral root primordia (LRP), initiated deep inside the root under the influence of the phytohormone auxin, is similarly dependent on cell wall dissolution to separate cells in the overlying tissues. It has been shown that this process also requires IDA, HAE, and HSL2. The receptors are redundant in function during floral organ abscission, but during lateral root emergence (LRE) they are differentially involved in regulating cell wall remodelling (CWR) genes. An overview is given here of the similarities and differences of IDA signalling during floral organ abscission and LRE.
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Affiliation(s)
- Reidunn B Aalen
- Department of Biosciences, University of Oslo, N-0316 Oslo, Norway
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Wang X, Liu D, Li A, Sun X, Zhang R, Wu L, Liang Y, Mao L. Transcriptome analysis of tomato flower pedicel tissues reveals abscission zone-specific modulation of key meristem activity genes. PLoS One 2013; 8:e55238. [PMID: 23390523 PMCID: PMC3563536 DOI: 10.1371/journal.pone.0055238] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Accepted: 12/28/2012] [Indexed: 01/26/2023] Open
Abstract
Tomato flower abscises at the anatomically distinct abscission zone that separates the pedicel into basal and apical portions. During abscission, cell separation occurs only at the abscission zone indicating distinctive molecular regulation in its cells. We conducted a transcriptome analysis of tomato pedicel tissues during ethylene promoted abscission. We found that the abscission zone was the most active site with the largest set of differentially expressed genes when compared with basal and apical portions. Gene Ontology analyses revealed enriched transcription regulation and hydrolase activities in the abscission zone. We also demonstrate coordinated responses of hormone and cell wall related genes. Besides, a number of ESTs representing homologs of key Arabidopsis shoot apical meristem activity genes were found to be preferentially expressed in the abscission zone, including WUSCHEL (WUS), KNAT6, LATERAL ORGAN BOUNDARIES DOMAIN PROTEIN 1(LBD1), and BELL-like homeodomain protein 1 (BLH1), as well as tomato axillary meristem genes BLIND (Bl) and LATERAL SUPPRESSOR (Ls). More interestingly, the homologs of WUS and the potential functional partner OVATE FAMILIY PROTEIN (OFP) were subsequently down regulated during abscission while Bl and AGL12 were continuously and specifically induced in the abscission zone. The expression patterns of meristem activity genes corroborate the idea that cells of the abscission zone confer meristem-like nature and coincide with the course of abscission and post-abscission cell differentiation. Our data therefore propose a possible regulatory scheme in tomato involving meristem genes that may be required not only for the abscission zone development, but also for abscission.
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Affiliation(s)
- Xiang Wang
- National Center for Wheat Research, Henan Agricultural University, Zhengzhou, People’s Republic of China
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, MOA Key Lab for Germplasm and Biotechnology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, People’s Republic of China
| | - Danmei Liu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, MOA Key Lab for Germplasm and Biotechnology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, People’s Republic of China
| | - Aili Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, MOA Key Lab for Germplasm and Biotechnology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, People’s Republic of China
| | - Xiuli Sun
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, MOA Key Lab for Germplasm and Biotechnology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, People’s Republic of China
- Key Laboratory of Symbol Computation and Knowledge Engineering of Ministry of Education, College of Computer Science and Technology, Jilin University, Changchun, People’s Republic of China
| | - Rongzhi Zhang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, MOA Key Lab for Germplasm and Biotechnology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, People’s Republic of China
| | - Liang Wu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, MOA Key Lab for Germplasm and Biotechnology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, People’s Republic of China
| | - Yanchun Liang
- Key Laboratory of Symbol Computation and Knowledge Engineering of Ministry of Education, College of Computer Science and Technology, Jilin University, Changchun, People’s Republic of China
| | - Long Mao
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, MOA Key Lab for Germplasm and Biotechnology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, People’s Republic of China
- * E-mail:
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Estornell LH, Agustí J, Merelo P, Talón M, Tadeo FR. Elucidating mechanisms underlying organ abscission. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 199-200:48-60. [PMID: 23265318 DOI: 10.1016/j.plantsci.2012.10.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 10/03/2012] [Accepted: 10/31/2012] [Indexed: 05/19/2023]
Abstract
Abscission consists in the detachment of entire vegetative and reproductive organs due to cell separation processes occurring at the abscission zones (AZs) at specific positions of the plant body. From an evolutionary point of view, abscission is a highly advantageous process resulting into fruit and seed dispersal as well as the shedding of no longer useful organs. In an agricultural context, however, abscission may become a major limiting factor for crop productivity. Domestication of major crops included the selection of plants that did not naturally shed ripe fruits or seeds. The understanding of abscission is of great importance to control seed and fruit production and to improve breeding and harvesting practices. Thus, advances made on model plants and crops are of major importance since they may provide potential candidate genes for further biotechnological applications. Here, we review the current knowledge of the physiological, genetic and genomic aspects related to abscission including the most recently disclosed putative regulators that appear to be implicated in the development and/or activation of the AZs.
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Affiliation(s)
- Leandro H Estornell
- Institut Valencià d'Investigacions Agràries (IVIA), Centre de Genómica, Apartat Oficial, Montcada (València), Spain
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33
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Ji H, Kim SR, Kim YH, Kim H, Eun MY, Jin ID, Cha YS, Yun DW, Ahn BO, Lee MC, Lee GS, Yoon UH, Lee JS, Lee YH, Suh SC, Jiang W, Yang JI, Jin P, McCouch SR, An G, Koh HJ. Inactivation of the CTD phosphatase-like gene OsCPL1 enhances the development of the abscission layer and seed shattering in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 61:96-106. [PMID: 19807881 DOI: 10.1111/j.1365-313x.2009.04039.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Although susceptibility to seed shattering causes severe yield loss during cereal crop harvest, it is an adaptive trait for seed dispersal in wild plants. We previously identified a recessive shattering locus, sh-h, from the rice shattering mutant line Hsh that carries an enhanced abscission layer. Here, we further mapped sh-h to a 34-kb region on chromosome 7 by analyzing 240 F(2) plants and five F(3) lines from the cross between Hsh and Blue&Gundil. Hsh had a point mutation at the 3' splice site of the seventh intron within LOC_Os07g10690, causing a 15-bp deletion of its mRNA as a result of altered splicing. Two transferred DNA (T-DNA) insertion mutants and one point mutant exhibited the enhanced shattering phenotype, confirming that LOC_Os07g10690 is indeed the sh-h gene. RNA interference (RNAi) transgenic lines with suppressed expression of this gene exhibited greater shattering. This gene, which encodes a protein containing a conserved carboxy-terminal domain (CTD) phosphatase domain, was named Oryza sativa CTD phosphatase-like 1 (OsCPL1). Subcellular localization and biochemical analysis revealed that the OsCPL1 protein is a nuclear phosphatase, a common characteristic of metazoan CTD phosphatases involved in cell differentiation. These results demonstrate that OsCPL1 represses differentiation of the abscission layer during panicle development.
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Affiliation(s)
- Hyeonso Ji
- Department of Agricultural Bio-resources, National Academy of Agricultural Science (NAAS), Suwon 441-707, Korea
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Dal Cin V, Barbaro E, Danesin M, Murayama H, Velasco R, Ramina A. Fruitlet abscission: A cDNA-AFLP approach to study genes differentially expressed during shedding of immature fruits reveals the involvement of a putative auxin hydrogen symporter in apple (Malus domestica L. Borkh). Gene 2009; 442:26-36. [DOI: 10.1016/j.gene.2009.04.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 04/08/2009] [Accepted: 04/14/2009] [Indexed: 10/20/2022]
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35
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HALL MA, MOSHKOV IE, NOVIKOVA GV, MUR LAJ, SMITH AR. Ethylene signal perception and transduction: multiple paradigms? Biol Rev Camb Philos Soc 2007. [DOI: 10.1111/j.1469-185x.2000.tb00060.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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36
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Meir S, Hunter DA, Chen JC, Halaly V, Reid MS. Molecular changes occurring during acquisition of abscission competence following auxin depletion in Mirabilis jalapa. PLANT PHYSIOLOGY 2006; 141:1604-16. [PMID: 16778017 PMCID: PMC1533941 DOI: 10.1104/pp.106.079277] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 06/02/2006] [Accepted: 06/05/2006] [Indexed: 05/10/2023]
Abstract
To understand how auxin regulates sensitivity of abscission zone (AZ) tissues to ethylene, we used a polymerase chain reaction-based subtractive approach to identify gene transcripts in Mirabilis jalapa AZs that changed in abundance during the time the zones became competent to abscise in response to exogenous ethylene. Transcript expression was then examined in leaf and stem AZs over the period they became ethylene competent following indole-3-acetic acid (IAA) depletion either by leaf deblading, treatment with the IAA transport inhibitor naphthylphthalamic acid, or cutting the stem above a node (decapitation). Transcripts down-regulated by deblading/decapitation included Mj-Aux/IAA1 and Mj-Aux/IAA2, encoding Aux/IAA proteins, and three other transcripts showing highest identity to a polygalacturonase inhibitor protein, a beta-expansin, and a beta-tubulin. Application of IAA to the cut end of petioles or stumps inhibited abscission, and prevented the decline in the levels of transcripts in both AZs. Transcripts up-regulated in the AZ following deblading/decapitation or treatment with naphthylphthalamic acid were isolated from plants pretreated with 1-methylcyclopropene before deblading to help select against ethylene-induced genes. Some of the up-regulated transcripts showed identity to proteins associated with ethylene or stress responses, while others did not show homology to known sequences. Sucrose infiltration of stem stumps enhanced abscission following ethylene treatment and also enhanced the induction of some of the up-regulated genes. Our results demonstrate a correlation between acquisition of competence to respond to ethylene in both leaf and stem AZs, and decline in abundance of auxin regulatory gene transcripts.
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Affiliation(s)
- Shimon Meir
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel.
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37
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Ji HS, Chu SH, Jiang W, Cho YI, Hahn JH, Eun MY, McCouch SR, Koh HJ. Characterization and mapping of a shattering mutant in rice that corresponds to a block of domestication genes. Genetics 2006; 173:995-1005. [PMID: 16582442 PMCID: PMC1526493 DOI: 10.1534/genetics.105.054031] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Easy shattering reduces yield due to grain loss during harvest in cereals. Shattering is also a hindrance in breeding programs that use wild accessions because the shattering habit is often linked to desirable traits. We characterized a shattering mutant line of rice, Hsh, which was derived from a nonshattering japonica variety, Hwacheong, by N-methyl-N-nitrosourea (MNU) treatment. The breaking tensile strength (BTS) of the grain pedicel was measured using a digital force gauge to evaluate the degree of shattering of rice varieties at 5, 10, 15, 20, 25, 30, 35, and 40 days after heading (DAH). The BTS of Hwacheong did not decrease with increasing DAH, maintaining a level of 180-240 gf, while that of Hsh decreased greatly during 10-20 DAH and finally stabilized at 50 gf. Optical microscopy revealed that Hsh had a well-developed abscission layer similar to the wild rice Oryza nivara (accession IRGC105706), while Hwacheong did not produce an abscission layer, indicating that the shattering of Hsh was caused by differentiation of the abscission layer. On the basis of the BTS value and morphology of the abscission layer of F(1) plants and segregation data in F(2) populations, it was concluded that the easy shattering of Hsh was controlled by the single recessive gene sh-h. The gene sh-h was determined to be located on rice chromosome 7 by bulked segregant analysis. Using 14 SSR markers on rice chromosome 7, the gene sh-h was mapped between the flanking markers RM8262 and RM7161 at distances of 1.6 and 2.0 cM, respectively. An SSR marker Rc17 cosegregated with the gene sh-h. The locus sh-h for shattering was tightly linked to the Rc locus conferring red pericarp, as well as a QTL qSD(s)-7-1 for seed dormancy, implying that this region might represent a domestication block in the evolutionary pathway of rice.
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Affiliation(s)
- Hyeon-So Ji
- National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon, Korea
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Lizana C, Wentworth M, Martinez JP, Villegas D, Meneses R, Murchie EH, Pastenes C, Lercari B, Vernieri P, Horton P, Pinto M. Differential adaptation of two varieties of common bean to abiotic stress: I. Effects of drought on yield and photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2006; 57:685-97. [PMID: 16415330 DOI: 10.1093/jxb/erj062] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The yield of 24 commercial varieties and accessions of common bean (Phaseolus vulgaris) has been determined at different sites in Chile and Bolivia. Statistical analysis was performed in order to characterize whether a particular variety was more or less stable in yield under different environmental conditions. Amongst these, two varieties have been identified for more detailed study: one variety has a higher than average yield under unstressed conditions but is strongly affected by stress, and another has a reduced yield under unstressed conditions but is less affected by stress. The contrasting rate of abscission of the reproductive organs under drought stress was clearly consistent with these differences. The more tolerant genotype shows a great deal of plasticity at the biochemical and cellular level when exposed to drought stress, in terms of stomatal conductance, photosynthetic rate, abscisic acid synthesis, and resistance to photoinhibition. By contrast, the former lacks such plasticity, but shows an enhanced tendency for a morphological response, the movement of leaves, which appears to be its principal response to drought stress.
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Affiliation(s)
- Carolina Lizana
- Facultad de Ciencias Agronómicas, Universidad de Chile, Casilla 1004, Santiago, Chile
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Yuan R, Wu Z, Kostenyuk IA, Burns JK. G-protein-coupled alpha2A-adrenoreceptor agonists differentially alter citrus leaf and fruit abscission by affecting expression of ACC synthase and ACC oxidase. JOURNAL OF EXPERIMENTAL BOTANY 2005; 56:1867-75. [PMID: 15928018 DOI: 10.1093/jxb/eri176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Temporal and spatial expression patterns of genes encoding 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS1 and ACS2) and ACC oxidase (ACO), ACC concentration, and ethylene production in leaves and fruit of 'Valencia' orange (Citrus sinensis [L.] Osbeck) were examined in relation to differential abscission after treatment with 2-chloroethylphosphonic acid (ethephon) alone or in combination with guanfacine or clonidine, two G-protein-coupled alpha(2A)-adrenoreceptor selective agonists. Guanfacine and clonidine markedly reduced ethephon-enhanced leaf abscission, but had little effect on ethephon-enhanced fruit loosening. Ethephon-enhanced fruit and leaf ethylene production, and ACC concentration in fruit abscission zones, fruit peel, leaf abscission zones, and leaf blades were decreased by guanfacine. Guanfacine reduced ethephon-enhanced expression of ACS1 and ACO genes in leaf abscission zones and blades, but to a lesser extent in fruit abscission zones. The expression pattern of the ACS2 gene, however, was not associated with abscission. The results demonstrate that differential expression of ACS1 and ACO genes is associated with reduction of ethephon-enhanced leaf abscission by guanfacine, and suggest a link between G-protein-related signalling and abscission.
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Affiliation(s)
- Rongcai Yuan
- University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred, FL 33850-2299, USA
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40
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Patterson SE, Bleecker AB. Ethylene-dependent and -independent processes associated with floral organ abscission in Arabidopsis. PLANT PHYSIOLOGY 2004; 134:194-203. [PMID: 14701913 PMCID: PMC316299 DOI: 10.1104/pp.103.028027] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2003] [Revised: 07/21/2003] [Accepted: 10/01/2003] [Indexed: 05/18/2023]
Abstract
Abscission is an important developmental process in the life cycle of the plant, regulating the detachment of organs from the main body of the plant. This mechanism can be initiated in response to environmental cues such as disease or pathogen, or it can be a programmed shedding of organs that no longer provide essential functions to the plant. We have identified five novel dab (delayed floral organ abscission) mutants (dab1-1, dab2-1, dab3-1, dab3-2, and dab3-3) in Arabidopsis. These mutants each display unique anatomical and physiological characteristics and are governed by three independent loci. Scanning electron microscopy shows delayed development of the flattened fracture plane in some mutants and irregular elongation in the cells of the fracture plane in other mutants. The anatomical observations are also supported by breakstrength measurements that show high breakstrength associated with broken cells, moderate levels for the flattened fracture plane, and low levels associated with the initial rounding of cells. In addition, observations on the expression patterns in the abscission zone of cell wall hydrolytic enzymes, chitinase and cellulose, show altered patterns in the mutants. Last, we have compared these mutants with the ethylene-insensitive mutants etr1-1 and ein2-1 to determine if ethylene is an essential component of the abscission process and find that although ethylene can accelerate abscission under many conditions, the perception of ethylene is not essential. The role of the dab genes and the ethylene response genes during the abscission process is discussed.
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Affiliation(s)
- Sara E Patterson
- Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706, USA.
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41
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González-Carranza ZH, Whitelaw CA, Swarup R, Roberts JA. Temporal and spatial expression of a polygalacturonase during leaf and flower abscission in oilseed rape and Arabidopsis. PLANT PHYSIOLOGY 2002; 128:534-43. [PMID: 11842157 PMCID: PMC148916 DOI: 10.1104/pp.010610] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2001] [Revised: 09/30/2001] [Accepted: 11/15/2001] [Indexed: 05/18/2023]
Abstract
During leaf abscission in oilseed rape (Brassica napus), cell wall degradation is brought about by the action of several hydrolytic enzymes. One of these is thought to be polygalacturonase (PG). Degenerate primers were used to isolate a PG cDNA fragment by reverse transcriptase-polymerase chain reaction from RNA extracted from ethylene-promoted leaf abscission zones (AZs), and in turn a full-length clone (CAW471) from an oilseed rape AZ cDNA library. The highest homology of this cDNA (82%) was to an Arabidopsis sequence that was predicted to encode a PG protein. Analysis of expression revealed that CAW471 mRNA accumulated in the AZ of leaves and reached a peak 24 h after ethylene treatment. Ethylene-promoted leaf abscission in oilseed rape was not apparent until 42 h after exposure to the gas, reaching 50% at 48 h and 100% by 56 h. In floral organ abscission, expression of CAW471 correlated with cell separation. Genomic libraries from oilseed rape and Arabidopsis were screened with CAW471 and the respective genomic clones PGAZBRAN and PGAZAT isolated. Characterization of these PG genes revealed that they had substantial homology within both the coding regions and in the 5'-upstream sequences. Fusion of a 1,476-bp 5'-upstream sequence of PGAZAT to beta-glucuronidase or green fluorescent protein and transformation of Arabidopsis revealed that this fragment was sufficient to drive expression of these reporter genes in the AZs at the base of the anther filaments, petals, and sepals.
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MESH Headings
- Amino Acid Sequence
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Arabidopsis/growth & development
- Brassica/enzymology
- Brassica/genetics
- Brassica/growth & development
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Plant/chemistry
- DNA, Plant/genetics
- Ethylenes/pharmacology
- Gene Expression Regulation, Developmental/drug effects
- Gene Expression Regulation, Enzymologic/drug effects
- Gene Expression Regulation, Plant/drug effects
- Molecular Sequence Data
- Phylogeny
- Plant Growth Regulators/pharmacology
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Leaves/growth & development
- Plant Stems/enzymology
- Plant Stems/genetics
- Plant Stems/growth & development
- Plants, Genetically Modified
- Polygalacturonase/genetics
- Polygalacturonase/metabolism
- Seeds/enzymology
- Seeds/genetics
- Seeds/growth & development
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Time Factors
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Affiliation(s)
- Zinnia Haydé González-Carranza
- Plant Science Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, United Kingdom
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Roberts JA, Elliott KA, Gonzalez-Carranza ZH. Abscission, dehiscence, and other cell separation processes. ANNUAL REVIEW OF PLANT BIOLOGY 2002; 53:131-58. [PMID: 12221970 DOI: 10.1146/annurev.arplant.53.092701.180236] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Cell separation is a critical process that takes place throughout the life cycle of a plant. It enables roots to emerge from germinating seeds, cotyledons, and leaves to expand, anthers to dehisce, fruit to ripen, and organs to be shed. The focus of this review is to examine how processes such as abscission and dehiscence are regulated and the ways new research strategies are helping us to understand the mechanisms involved in bringing about a reduction in cell-to-cell adhesion. The opportunities for using this information to manipulate cell separation for the benefit of agriculture and horticulture are evaluated.
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Affiliation(s)
- Jeremy A Roberts
- Division of Plant Science, School of Biosciences, Sutton Bonington Campus, University of Nottingham, Loughborough, Leics LE12 5RD, United Kingdom.
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43
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Henderson J, Lyne L, Osborne DJ. Failed expression of an endo-beta-1,4-glucanhydrolase (cellulase) in a non-abscinding mutant of Lupinus angustifolius cv Danja. PHYTOCHEMISTRY 2001; 58:1025-1034. [PMID: 11730865 DOI: 10.1016/s0031-9422(01)00384-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cellulase expressions in a normal shedding wild-type and a non-abscinding single gene mutant of Lupinus angustifolius have been studied during ethylene treatments of leaf abscission zone explants. Of the range of different glycohydrolases investigated only the abscission cell-specific beta-1,4-glucanhydrolase (cellulase) was not produced in the non-abscinding mutant. An endo-polygalacturonase was induced equally in both wild-type and mutant and other glycohydrolases were equally up-regulated. The abscission cell-specific cellulase induced at shedding of wild-type is antigenically similar to the Phaseolus vulgaris induced leaf abscission pI 9.5 cellulase but with a higher molecular mass (50 kD compared with 48 kD) and like the bean abscission-specific cellulase that of lupin is not glycosylated. Causes of the loss of function of cellulase expression in the non-shedding mutant are discussed.
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Affiliation(s)
- J Henderson
- Oxford Research Unit, Open University, Foxcombe Hall, Boars Hill, Oxford, OX1 5HR, UK
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Michaeli R, Philosoph-Hadas S, Riov J, Shahak Y, Ratner K, Meir S. Chilling-induced leaf abscission of Ixora coccinea plants. III. Enhancement by high light via increased oxidative processes. PHYSIOLOGIA PLANTARUM 2001; 113:338-345. [PMID: 12060278 DOI: 10.1034/j.1399-3054.2001.1130306.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The role of increased oxidation induced by successive stresses of chilling and high light in the induction of leaf abscission was studied in Ixora coccinea plants in relation to auxin metabolism and oxidative processes. Exposure of plants following dark chilling (7 degrees C for 3 days) to high light (500-700 &mgr;mol m-2 s-1 photosynthetically active radiation) for 5 h at 20-25 degrees C enhanced chilling-induced leaf abscission. This abscission was inhibited by pretreatment with the antioxidant butylated hydroxyanisole, alpha-naphthaleneacetic acid or the ethylene action inhibitor, 1-methylcyclopropene. The oxidative processes initiated during the low light period following the dark chilling period, such as indoleacetic acid (IAA) decarboxylation and lipid peroxidation, were further enhanced by subsequent exposure to high light. Photoinhibition, expressed by the reduction of the chlorophyll fluorescence parameter Fv/Fm, was evident following exposure to high light, irrespective of the temperature of the pretreatment, but this reduction persisted only in chilled plants. This suggests that oxidative processes generated during and after the chilling period might have inhibited the recovery from photoinhibition. The chilling stress under darkness induced a 60% reduction in superoxide dismutase (SOD) activity and significant increases (130-600%) in the activities of several other antioxidative enzymes. These data suggest that the chilling-induced reduction in SOD activity may well be responsible for the increase in the oxidative stress induced by the subsequent light treatment, as expressed by the increased enzymatic activities. Taken together, this study provides further support for the involvement of oxidative processes in the events occurring in tissues exposed to sequential chilling and light stresses, leading to reduction in free IAA content in the abscission zone and to leaf abscission.
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Affiliation(s)
- Rina Michaeli
- Department of Postharvest Science of Fresh Produce, ARO, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel The Kennedy-Leigh Centre for Horticultural Research, Faculty of Agriculture, The Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel Institute of Horticulture, ARO, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
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45
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Patterson SE. Cutting loose. Abscission and dehiscence in Arabidopsis. PLANT PHYSIOLOGY 2001; 126:494-500. [PMID: 11402180 PMCID: PMC1540116 DOI: 10.1104/pp.126.2.494] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Affiliation(s)
- S E Patterson
- Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706-1381, USA.
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46
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Henderson J, Davies HA, Heyes SJ, Osborne DJ. The study of a monocotyledon abscission zone using microscopic, chemical, enzymatic and solid state 13C CP/MAS NMR analyses. PHYTOCHEMISTRY 2001; 56:131-139. [PMID: 11219806 DOI: 10.1016/s0031-9422(00)00447-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We have investigated distinguishing features in cells of the abscission zone of a monocotyledon fruit, the oil palm Elaeis guineensis. The cell walls of the abscission zone and the subtending mesocarp and pedicel have been analysed by light and transmission electron microscopy, by chemical methods and by solid state 13C CP/MAS NMR spectroscopy. Results show that these abscission zone cells have specific characteristics which include high levels of unmethylated pectin in the walls and an inducible (x35) polygalacturonase enzyme expression. Together these findings help to explain the localised precision of cell separation events.
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47
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Uheda E, Nakamura S. Abscission of Azolla branches induced by ethylene and sodium azide. PLANT & CELL PHYSIOLOGY 2000; 41:1365-1372. [PMID: 11134422 DOI: 10.1093/pcp/pcd071] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Treatment with ethylene accelerated the abscission of branches of Azolla filiculoides plants. An Azolla plantlet treated with ethylene at 10 microl liter(-1) divided into 4-5 fragments after a lag period of 6-8 h. Ethylene-induced abscission was effectively inhibited by cycloheximide and was associated with an increase in the activities of cellulase and polygalacturonase. At the fracture surface abscised after treatment with ethylene, dissolution of the primary walls of the abscission zone cells was apparent. However, the middle lamella between abscission zone cells was still present. Immunoelectron microscopy using anti-unesterified pectin (JIM5) and anti-methylesterified pectin (JIM7) monoclonal antibodies revealed the presence of both JIM5 and JIM7 epitopes in the wall between abscission zone cells of branches before abscission occurred. In the middle lamella remaining after ethylene-induced abscission, only JIM7 epitopes were observed. The features of ethylene-induced abscission described herein were different from those of the rapid abscission induced by sodium azide, which implies that they are mediated by different mechanisms. The possible mechanisms are discussed.
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Affiliation(s)
- E Uheda
- Research Institute for Advanced Science and Technology, University of Osaka Prefecture, Gakuen-cho, Sakai, Osaka, 593 Japan.
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48
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André JP, Catesson AM, Liberman M. Characters and origin of vessels with heterogenous structure in leaf and flower abscission zones. ACTA ACUST UNITED AC 1999. [DOI: 10.1139/b98-213] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The lifetime of many plant organs does not exceed a few weeks or a few months. These organs separate from the plant at the level of specialized abscission zones. The observation of xylem vasculature in abscission zones, a largely neglected subject, revealed original features when a vessel casting method was used. In all species of dicotyledons examined so far, flower and leaf abscission zones possessed heterogenous metaxylem vessels adjoining protoxylem and secondary xylem vessels with homogenous patterns of lignified thickenings. Heterogenous metaxylem vessel thickenings were helical, reticulate, or scalariform elements when in the abscission zone and pitted elements on the proximal and the distal sides. The origin and possible role of these vessels are considered. Data obtained on the flower abscission zone of tomato (Lycopersicon esculentum Mill.) suggest that formation of heterogenous vessels results from localized changes in the rhythm of cell differentiation and cell maturation inside the procambium-cambium continuum.Key words: abscission zone, cambium, differentiation, heterogenous vessels, procambium, vessel cast.
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49
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Affiliation(s)
- J E Thompson
- Department of Biology, University of Waterloo, Ontario, Canada
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50
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Uheda E, Akasaka Y, Daimon H. Morphological aspects of the shedding of surface layers from peanut roots. ACTA ACUST UNITED AC 1997. [DOI: 10.1139/b97-067] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epidermal cells and cells originating in the outer cortex form the surface layers of peanut (Arachis hypogaea) roots, the outermost of which separate and shed from the periphery. Shedding takes place continuously and over the whole surface of the root. Light and electron microscopic studies revealed that the shedding of surface layers involves modification of cell walls and separation of intact cells. Wall breakdown, as well as the expansion of cells resulting from wall breakdown, might facilitate the separation of intact cells. Examination of enzymes revealed that cellulase showed much higher activity in the shedding layers than in the remaining tissues. The results suggest that the cell separation process in peanut roots involves a wall-degrading enzyme-mediated mechanism. Key words: Arachis hypogaea, morphology, root, shedding, surface layers, wall breakdown.
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