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Low Temperature Inhibits the Defoliation Efficiency of Thidiazuron in Cotton by Regulating Plant Hormone Synthesis and the Signaling Pathway. Int J Mol Sci 2022; 23:ijms232214208. [PMID: 36430686 PMCID: PMC9694417 DOI: 10.3390/ijms232214208] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/03/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
Thidiazuron (TDZ) is the main defoliant used in production to promote leaf abscission for machine-picked cotton. Under low temperatures, the defoliation rate of cotton treated with TDZ decreases and the time of defoliation is delayed, but there is little information about this mechanism. In this study, RNA-seq and physiological analysis are performed to reveal the transcriptome profiling and change in endogenous phytohormones upon TDZ treatment in abscission zones (AZs) under different temperatures (daily mean temperatures: 25 °C and 15 °C). Genes differentially expressed in AZs between TDZ treatment and control under different temperatures were subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to compare the enriched GO terms and KEGG pathways between the two temperature conditions. The results show that, compared with the corresponding control group, TDZ induces many differentially expressed genes (DEGs) in AZs, and the results of the GO and KEGG analyses show that the plant hormone signaling transduction pathway is significantly regulated by TDZ. However, under low temperature, TDZ induced less DEGs, and the enriched GO terms and KEGG pathways were different with those under normal temperature condition. Many genes in the plant hormone signal transduction pathway could not be induced by TDZ under low temperature conditions. In particular, the upregulated ethylene-signaling genes and downregulated auxin-signaling genes in AZs treated with TDZ were significantly affected by low temperatures. Furthermore, the expression of ethylene and auxin synthesis genes and their content in AZs treated with TDZ were also regulated by low temperature conditions. The upregulated cell wall hydrolase genes induced by TDZ were inhibited by low temperatures. However, the inhibition of low temperature on genes in AZs treated with TDZ was relieved with the extension of the treatment time. Together, these results indicate that the responses of ethylene and auxin synthesis and the signaling pathway to TDZ are inhibited by low temperatures, which could not induce the expression of cell wall hydrolase genes, and then inhibit the separation of AZ cells and the abscission of cotton leaves. This result provides new insights into the mechanism of defoliation induced by TDZ under low temperature conditions.
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Yan F, Gong Z, Hu G, Ma X, Bai R, Yu R, Zhang Q, Deng W, Li Z, Wuriyanghan H. Tomato SlBL4 plays an important role in fruit pedicel organogenesis and abscission. HORTICULTURE RESEARCH 2021; 8:78. [PMID: 33790250 PMCID: PMC8012377 DOI: 10.1038/s41438-021-00515-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/08/2021] [Accepted: 02/06/2021] [Indexed: 05/21/2023]
Abstract
Abscission, a cell separation process, is an important trait that influences grain and fruit yield. We previously reported that BEL1-LIKE HOMEODOMAIN 4 (SlBL4) is involved in chloroplast development and cell wall metabolism in tomato fruit. In the present study, we showed that silencing SlBL4 resulted in the enlargement and pre-abscission of the tomato (Solanum lycopersicum cv. Micro-TOM) fruit pedicel. The anatomic analysis showed the presence of more epidermal cell layers and no obvious abscission zone (AZ) in the SlBL4 RNAi lines compared with the wild-type plants. RNA-seq analysis indicated that the regulation of abscission by SlBL4 was associated with the altered abundance of genes related to key meristems, auxin transporters, signaling components, and cell wall metabolism. Furthermore, SlBL4 positively affected the auxin concentration in the abscission zone. A dual-luciferase reporter assay revealed that SlBL4 activated the transcription of the JOINTLESS, OVATE, PIN1, and LAX3 genes. We reported a novel function of SlBL4, which plays key roles in fruit pedicel organogenesis and abscission in tomatoes.
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Affiliation(s)
- Fang Yan
- Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Science, Inner Mongolia University, Hohhot, 010021, China
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Zhehao Gong
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Guojian Hu
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Xuesong Ma
- Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Science, Inner Mongolia University, Hohhot, 010021, China
| | - Runyao Bai
- Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Science, Inner Mongolia University, Hohhot, 010021, China
| | - Ruonan Yu
- Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Science, Inner Mongolia University, Hohhot, 010021, China
| | - Qiang Zhang
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Wei Deng
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, 401331, Chongqing, China
| | - Zhengguo Li
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, 401331, Chongqing, China.
- Center of Plant Functional Genomics, Institute of Advanced Interdisciplinary Studies, Chongqing University, 401331, Chongqing, China.
| | - Hada Wuriyanghan
- Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Science, Inner Mongolia University, Hohhot, 010021, China.
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Parra R, Gomez-Jimenez MC. Spatio-temporal immunolocalization of extensin protein and hemicellulose polysaccharides during olive fruit abscission. PLANTA 2020; 252:32. [PMID: 32757074 DOI: 10.1007/s00425-020-03439-6] [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: 05/27/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
Immunocytochemical and molecular analyses reveal that the disassembly of the cell wall may be mediated by changes in the level and subcellular location of extensin protein and hemicelluloses during olive-fruit abscission. Although cell-wall modification is believed to underlie the changes in organ abscission, information concerning the changes in cell-wall proteins and hemicellulose polysaccharides is still limited. The aim of this work was to analyze the spatio-temporal patterns of the distribution of different extensin proteins and hemicelluloses in the abscission zone (AZ) during natural ripe-fruit abscission in olive (Olea europaea L.). In this study, we employed immunogold labeling in the ripe-fruit AZ during olive AZ cell separation, using an expanded set of monoclonal antibodies that recognize different types of hemicelluloses (LM11, LM15, and LM21), callose (anti-(1,3)-β-D-glucan) and extensin (JIM19) epitopes, and transmission electron microscopy imaging. Our data demonstrate that AZ cell separation was accompanied by a loss of the JIM19 extensin epitopes and a reduction in the detection of the LM15 xyloglucan epitopes in AZ cell walls, whereas AZ cells were found to be enriched with respect to the xylan and callose levels of the cell wall during olive ripe-fruit abscission. By contrast, AZ cell-wall polysaccharide remodeling did not involve mannans. Moreover, in ripe-fruit AZ, quantitative RT-PCR analysis revealed that OeEXT1, OeEXT2, OeXTH9, and OeXTH13 genes were downregulated during abscission, whereas the expression of OeXTH1, OeXTH5, and OeXTH14 genes increased during abscission. Taken together, the results indicate that AZ cell-wall dynamics during olive ripe-fruit abscission involves extensin protein and hemicellulose modifications, as well as related expressed genes. This is the first study available demonstrating temporal degradation of extensin protein and hemicelluloses in the AZ at the subcellular level.
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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
| | - 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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Ma X, Yuan Y, Wu Q, Wang J, Li J, Zhao M. LcEIL2/3 are involved in fruitlet abscission via activating genes related to ethylene biosynthesis and cell wall remodeling in litchi. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1338-1350. [PMID: 32391616 DOI: 10.1111/tpj.14804] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 04/07/2020] [Accepted: 04/28/2020] [Indexed: 05/28/2023]
Abstract
Fruit crops are subject to precocious fruit abscission, during which the phytohormone ethylene (ET) acts as a major positive regulator. However, the molecular basis of ET-induced fruit abscission remains poorly understood. Here, we show that two ETHYLENE INSENSITIVE 3-like (EIL) homologs in litchi, LcEIL2 and LcEIL3, play a role in ET-activated fruitlet abscission. LcEIL2/3 were significantly upregulated in the fruit abscission zone (AZ) during the ET-induced fruitlet abscission in litchi. The presence of LcEIL2/3 in wild-type Arabidopsis and ein3 eil1 mutants can accelerate the floral organ abscission. Moreover, the electrophoretic mobility shift assay and dual luciferase reporter analysis illustrated that LcEIL2/3 directly interacted with the gene promoters to activate the expression of cell wall remodeling genes LcCEL2/8 and LcPG1/2, and ET biosynthetic genes LcACS1/4/7 and LcACO2/3. Furthermore, we showed that LcPG1/2 were expressed in the floral abscission zone of Arabidopsis, and constitutive expression of LcPG2 in Arabidopsis promoted the floral organ abscission. In conclusion, we propose that LcEIL2/3 are involved in ET-induced fruitlet abscission via controlling expression of genes related to ET biosynthesis and cell wall remodeling in litchi.
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Affiliation(s)
- 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
| | - Ye Yuan
- 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
| | - Qian Wu
- 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
| | - Jun 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 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 Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
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Chersicola M, Kladnik A, Tušek Žnidarič M, Lers A, Dermastia M, Hause B. The pattern of 1-aminocyclopropane-1-carboxylate oxidase induction in the tomato leaf petiole abscission zone is independent of expression of the ribonuclease-LX-encoding LeLX gene. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:722-728. [PMID: 29633546 PMCID: PMC6032998 DOI: 10.1111/plb.12730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/26/2018] [Accepted: 03/30/2018] [Indexed: 06/08/2023]
Abstract
The abscission of tomato leaves occurs in the petiole abscission zone, and its late stage includes two spatially divided processes: cell separation and programmed cell death (PCD). Both of these processes are regulated by ethylene. The last step in ethylene biosynthesis is conversion of 1-aminocyclopropane-1-carboxylic acid to ethylene, which is catalysed by the enzyme 1-aminocyclopropane-1-carboxylate oxidase (ACO); however, the location of ACO in the leaf petiole abscission zone is not known. The tomato gene LeLX encodes ribonuclease LX, which is a marker for PCD and is induced by ethylene during abscission, but its association with ACO has not been explored. In a tomato transgenic line 1-7 with inhibited expression of LeLX showing delayed leaf abscission, the morphology and ultrastructure of the leaf petiole abscission zone was examined. In this zone of the cv.'VF36' and of a transgenic line 1-7, spatiotemporal differences in expression of LeACO1 and LeACO4 were analysed and ACO protein was detected immunohistochemically. In comparison to wild-type plants, there were no obvious morphological and ultrastructural features in the abscission zone of plants of a transgenic line 1-7 before and after abscission induction. LeACO1 expression was low before abscission induction, and increased 24 h after induction, although with no apparent spatial pattern. In contrast, LeACO4 was expressed before abscission induction, and its transcript level declined 24 h after induction on the distal side of the abscission zone fracture. In the LeLX-inhibited transgenic line, there were no significant differences in LeACO1 and LeACO4 expression in the petiole abscission zone, in comparison to wild-type plants. In addition, the ACO protein was immunolocalised to the vascular tissues that traverse the petiole abscission zone in plants of wild type and of a transgenic line 1-7; and additionally in the plane of future abscission zone fracture of transgenic-line plants. The results suggest temporal differential expression of the LeACO genes in tomato leaf petioles and vascular localisation of ACO1 protein. Additionally, the results indicate that expression of LeACO genes is not affected by suppression of the LeLX expression.
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Affiliation(s)
- M. Chersicola
- Department of Biotechnology and Systems BiologyNational Institute of BiologyLjubljanaSlovenia
- Jožef Stefan International Postgraduate SchoolLjubljanaSlovenia
| | - A. Kladnik
- Department of BiologyBiotechnical FacultyUniversity of LjubljanaLjubljanaSlovenia
| | - M. Tušek Žnidarič
- Department of Biotechnology and Systems BiologyNational Institute of BiologyLjubljanaSlovenia
| | - A. Lers
- Department of Postharvest Science of Fresh ProduceAgricultural Research OrganizationThe Volcani CenterRishon LeZionIsrael
| | - M. Dermastia
- Department of Biotechnology and Systems BiologyNational Institute of BiologyLjubljanaSlovenia
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Chersicola M, Kladnik A, Tušek Žnidarič M, Mrak T, Gruden K, Dermastia M. 1-Aminocyclopropane-1-Carboxylate Oxidase Induction in Tomato Flower Pedicel Phloem and Abscission Related Processes Are Differentially Sensitive to Ethylene. FRONTIERS IN PLANT SCIENCE 2017; 8:464. [PMID: 28408916 PMCID: PMC5374216 DOI: 10.3389/fpls.2017.00464] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/16/2017] [Indexed: 06/07/2023]
Abstract
Ethylene has impact on several physiological plant processes, including abscission, during which plants shed both their vegetative and reproductive organs. Cell separation and programmed cell death are involved in abscission, and these have also been correlated with ethylene action. However, the detailed spatiotemporal pattern of the molecular events during abscission remains unknown. We examined the expression of two tomato ACO genes, LeACO1, and LeACO4 that encode the last enzyme in ethylene biosynthesis, 1-aminocyclopropane-1-carboxylate oxidase (ACO), together with the expression of other abscission-associated genes involved in cell separation and programmed cell death, during a period of 0-12 h after abscission induction in the tomato flower pedicel abscission zone and nearby tissues. In addition, we determined their localization in specific cell layers of the flower pedicel abscission zone and nearby tissues obtained by laser microdissection before and 8 h after abscission induction. The expression of both ACO genes was localized to the vascular tissues in the pedicel. While LeACO4 was more uniformly expressed in all examined cell layers, the main expression site of LeACO1 was in cell layers just outside the abscission zone in its proximal and distal part. We showed that after abscission induction, ACO1 protein was synthesized in phloem companion cells, in which it was localized mainly in the cytoplasm. Samples were additionally treated with 1-methylcyclopropene (1-MCP), a competitive inhibitor of ethylene actions, and analyzed 8 h after abscission induction. Cell-layer-specific changes in gene expression were observed together with the specific localization and ethylene sensitivity of the hallmarks of cell separation and programmed cell death. While treatment with 1-MCP prevented separation of cells through inhibition of the expression of polygalacturonases, which are the key enzymes involved in degradation of the middle lamella, this had less impact on the occurrence of different kinds of membrane vesicles and abscission-related programmed cell death. In the flower pedicel abscission zone, the physical progressions of cell separation and programmed cell death are perpendicular to each other and start in the vascular tissues.
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Affiliation(s)
- Marko Chersicola
- Department of Biotechnology and Systems Biology, National Institute of BiologyLjubljana, Slovenia
- Jožef Stefan International Postgraduate SchoolLjubljana, Slovenia
| | - Aleš Kladnik
- Department of Biology, Biotechnical Faculty, University of LjubljanaLjubljana, Slovenia
| | - Magda Tušek Žnidarič
- Department of Biotechnology and Systems Biology, National Institute of BiologyLjubljana, Slovenia
| | - Tanja Mrak
- Department of Forest Physiology and Genetics, Slovenian Forestry InstituteLjubljana, Slovenia
| | - Kristina Gruden
- Department of Biotechnology and Systems Biology, National Institute of BiologyLjubljana, Slovenia
- Jožef Stefan International Postgraduate SchoolLjubljana, Slovenia
| | - Marina Dermastia
- Department of Biotechnology and Systems Biology, National Institute of BiologyLjubljana, Slovenia
- Jožef Stefan International Postgraduate SchoolLjubljana, Slovenia
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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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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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Tucker ML, Yang R. IDA-like gene expression in soybean and tomato leaf abscission and requirement for a diffusible stelar abscission signal. AOB PLANTS 2012; 2012:pls035. [PMID: 23585923 PMCID: PMC3624929 DOI: 10.1093/aobpla/pls035] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 09/25/2012] [Indexed: 05/19/2023]
Abstract
BACKGROUND AND AIMS The stimulatory and inhibitory role of ethylene and auxin, respectively, in leaf abscission (leaf drop) is well documented. More recently, IDA (INFLORESCENCE DEFICIENT IN ABSCISSION) peptides and their putative interacting receptor-like-kinase partners, HAESA and HAESA-like2, were shown to be essential components in Arabidopsis floral organ abscission. Prior to research on IDA, it was reported that bean (Phaseolus vulgaris) leaf abscission required a diffusible signal that emanated from the vascular tissue. We were interested in determining whether the IDA signalling path might regulate abscission in plants other than Arabidopsis and whether IDA might act as a diffusible signal in abscission. METHODOLOGY Quantitative polymerase chain reaction was used to monitor gene expression and a GUS reporter gene construct used to determine the need for a diffusible signal in tomato. PRINCIPAL RESULTS We identified 12 IDA-like and 11 HAESA-like genes in soybean (Glycine max) and monitored their gene expression in abscission in relation to the expression of several cell-wall-modifying proteins and aminocyclopropane-1-carboxylic acid synthases. Ethylene evoked the expression of several IDA-like genes in abscission zones (AZ), but also to a lesser degree in the adjacent petiole tissue. Surprisingly, IDA-like gene expression was very high in senescent soybean leaves. We identified five IDA-like genes in tomato (Solanum lycopersicum). Only one IDA-like gene was expressed in the tomato AZ and its expression was approximately equal in the AZ and petioles, but no IDA-like gene showed significant expression in leaves at up to 96 h of exposure to ethylene. CONCLUSIONS IDA-like gene expression is up-regulated during soybean and tomato abscission but up-regulation was not limited to the AZ. Cell separation in the AZ cortex of tomato does not require a diffusible signal emanating from the stele. A role for IDA in soybean and tomato leaf abscission is discussed.
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