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Li YT, Liu DH, Luo Y, Abbas Khan M, Mahmood Alam S, Liu YZ. Transcriptome analysis reveals the key network of axillary bud outgrowth modulated by topping in citrus. Gene 2024; 926:148623. [PMID: 38821328 DOI: 10.1016/j.gene.2024.148623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 05/14/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
Topping, an important tree shaping and pruning technique, can promote the outgrowth of citrus axillary buds. However, the underlying molecular mechanism is still unclear. In this study, spring shoots of Citrus reticulata 'Huagan No.2' were topped and transcriptome was compared between axillary buds of topped and untopped shoots at 6 and 11 days after topping (DAT). 1944 and 2394 differentially expressed genes (DEGs) were found at 6 and 11 DAT, respectively. KEGG analysis revealed that many DEGs were related to starch and sucrose metabolism, signal transduction of auxin, cytokinin and abscisic acid. Specially, transcript levels of auxin synthesis, transport, and signaling-related genes (SAURs and ARF5), cytokinin signal transduction related genes (CRE1, AHP and Type-A ARRs), ABA signal responsive genes (PYL and ABF) were up-regulated by topping; while transcript levels of auxin receptor TIR1, auxin responsive genes AUX/IAAs, ABA signal transduction related gene PP2Cs and synthesis related genes NCED3 were down-regulated. On the other hand, the contents of sucrose and fructose in axillary buds of topped shoots were significantly higher than those in untopped shoots; transcript levels of 16 genes related to sucrose synthase, hexokinase, sucrose phosphate synthase, endoglucanase and glucosidase, were up-regulated in axillary buds after topping. In addition, transcript levels of genes related to trehalose 6-phosphate metabolism and glycolysis/tricarboxylic acid (TCA) cycle, as well to some transcription factors including Pkinase, Pkinase_Tyr, Kinesin, AP2/ERF, P450, MYB, NAC and Cyclin_c, significantly responded to topping. Taken together, the present results suggested that topping promoted citrus axillary bud outgrowth through comprehensively regulating plant hormone and carbohydrate metabolism, as well as signal transduction. These results deepened our understanding of citrus axillary bud outgrowth by topping and laid a foundation for further research on the molecular mechanisms of citrus axillary bud outgrowth.
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Affiliation(s)
- Yan-Ting Li
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Dong-Hai Liu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yin Luo
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Muhammad Abbas Khan
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Shariq Mahmood Alam
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yong-Zhong Liu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China.
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Wang M, Li J, Li T, Kang S, Jiang S, Huang J, Tang H. Light Supplementation in Pitaya Orchards Induces Pitaya Flowering in Winter by Promoting Phytohormone Biosynthesis. Int J Mol Sci 2024; 25:4794. [PMID: 38732009 PMCID: PMC11083671 DOI: 10.3390/ijms25094794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024] Open
Abstract
The interaction between light and phytohormones is crucial for plant growth and development. The practice of supplementing light at night during winter to promote pitaya flowering and thereby enhance yield has been shown to be crucial and widely used. However, it remains unclear how supplemental winter light regulates phytohormone levels to promote flowering in pitaya. In this study, through analyzing the transcriptome data of pitaya at four different stages (NL, L0, L1, L2), we observed that differentially expressed genes (DEGs) were mainly enriched in the phytohormone biosynthesis pathway. We further analyzed the data and found that cytokinin (CK) content first increased at the L0 stage and then decreased at the L1 and L2 stages after supplemental light treatment compared to the control (NL). Gibberellin (GA), auxin (IAA), salicylic acid (SA), and jasmonic acid (JA) content increased during the formation of flower buds (L1, L2 stages). In addition, the levels of GA, ethylene (ETH), IAA, and abscisic acid (ABA) increased in flower buds after one week of development (L2f). Our results suggest that winter nighttime supplemental light can interact with endogenous hormone signaling in pitaya, particularly CK, to regulate flower bud formation. These results contribute to a better understanding of the mechanism of phytohormone interactions during the induction of flowering in pitaya under supplemental light in winter.
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Affiliation(s)
- Meng Wang
- Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; (M.W.); (J.L.); (T.L.); (S.K.); (S.J.)
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Jiaxue Li
- Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; (M.W.); (J.L.); (T.L.); (S.K.); (S.J.)
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Tao Li
- Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; (M.W.); (J.L.); (T.L.); (S.K.); (S.J.)
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Shaoling Kang
- Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; (M.W.); (J.L.); (T.L.); (S.K.); (S.J.)
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Senrong Jiang
- Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; (M.W.); (J.L.); (T.L.); (S.K.); (S.J.)
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Jiaquan Huang
- Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; (M.W.); (J.L.); (T.L.); (S.K.); (S.J.)
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Hua Tang
- Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; (M.W.); (J.L.); (T.L.); (S.K.); (S.J.)
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
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Tang J, Chen Y, Huang C, Li C, Feng Y, Wang H, Ding C, Li N, Wang L, Zeng J, Yang Y, Hao X, Wang X. Uncovering the complex regulatory network of spring bud sprouting in tea plants: insights from metabolic, hormonal, and oxidative stress pathways. FRONTIERS IN PLANT SCIENCE 2023; 14:1263606. [PMID: 37936941 PMCID: PMC10627156 DOI: 10.3389/fpls.2023.1263606] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 09/26/2023] [Indexed: 11/09/2023]
Abstract
The sprouting process of tea buds is an essential determinant of tea quality and taste, thus profoundly impacting the tea industry. Buds spring sprouting is also a crucial biological process adapting to external environment for tea plants and regulated by complex transcriptional and metabolic networks. This study aimed to investigate the molecular basis of bud sprouting in tea plants firstly based on the comparisons of metabolic and transcriptional profiles of buds at different developmental stages. Results notably highlighted several essential processes involved in bud sprouting regulation, including the interaction of plant hormones, glucose metabolism, and reactive oxygen species scavenging. Particularly prior to bud sprouting, the accumulation of soluble sugar reserves and moderate oxidative stress may have served as crucial components facilitating the transition from dormancy to active growth in buds. Following the onset of sprouting, zeatin served as the central component in a multifaceted regulatory mechanism of plant hormones that activates a range of growth-related factors, ultimately leading to the promotion of bud growth. This process was accompanied by significant carbohydrate consumption. Moreover, related key genes and metabolites were further verified during the entire overwintering bud development or sprouting processes. A schematic diagram involving the regulatory mechanism of bud sprouting was ultimately proposed, which provides fundamental insights into the complex interactions involved in tea buds.
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Affiliation(s)
- Junwei Tang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Yao Chen
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Chao Huang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Congcong Li
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Yue Feng
- Zhejiang Provincial Seed Management Station, Hangzhou, China
| | - Haoqian Wang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Changqing Ding
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Nana Li
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Lu Wang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Jianming Zeng
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Yajun Yang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Xinyuan Hao
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Xinchao Wang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs/National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
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Bao Y, Li X, Qi X, Wang X, Feng X, Chen Y, Hou L, Li M. Analysis of cytokinin content and associated genes at different developmental stages in pak choi ( Brassica rapa ssp. chinensis Makino). BIOTECHNOL BIOTEC EQ 2022. [DOI: 10.1080/13102818.2022.2106888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Affiliation(s)
- Yue Bao
- College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, PR China
- Collaborative Innovation Center for Improving Quality and Increasing Profits of Protected Vegetables in Shanxi, Taigu, Shanxi, PR China
| | - Xuan Li
- College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, PR China
- Collaborative Innovation Center for Improving Quality and Increasing Profits of Protected Vegetables in Shanxi, Taigu, Shanxi, PR China
| | - Xianhui Qi
- College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, PR China
- Collaborative Innovation Center for Improving Quality and Increasing Profits of Protected Vegetables in Shanxi, Taigu, Shanxi, PR China
| | - Xueting Wang
- College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, PR China
- Collaborative Innovation Center for Improving Quality and Increasing Profits of Protected Vegetables in Shanxi, Taigu, Shanxi, PR China
| | - Xianjun Feng
- College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, PR China
- Collaborative Innovation Center for Improving Quality and Increasing Profits of Protected Vegetables in Shanxi, Taigu, Shanxi, PR China
| | - Yinglong Chen
- The UWA Institute of Agriculture, and School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
| | - Leiping Hou
- College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, PR China
- Collaborative Innovation Center for Improving Quality and Increasing Profits of Protected Vegetables in Shanxi, Taigu, Shanxi, PR China
| | - Meilan Li
- College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi, PR China
- Collaborative Innovation Center for Improving Quality and Increasing Profits of Protected Vegetables in Shanxi, Taigu, Shanxi, PR China
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Yang L, Zhu S, Xu J. Roles of auxin in the inhibition of shoot branching in 'Dugan' fir. TREE PHYSIOLOGY 2022; 42:1411-1431. [PMID: 35088089 DOI: 10.1093/treephys/tpac008] [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: 09/01/2021] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
Shoot branching substantially impacts vegetative and reproductive growth as well as wood characteristics in perennial woody species by shaping the shoot system architecture. Although plant hormones have been shown to play a fundamental role in shoot branching in annual species, their corresponding actions in perennial woody plants are largely unknown, in part due to the lack of branching mutants. Here, we demonstrated the role of plant hormones in bud dormancy transition toward activation and outgrowth in woody plants by comparing the physiological and molecular changes in the apical shoot stems of 'Yangkou' 020 fir and 'Dugan' fir, two Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) clones with normal and completely abolished branching phenotypes, respectively. Our studies showed that the defect in bud outgrowth was the cause of failed shoot branching in 'Dugan' fir whereas apically derived signals acted as triggers of this ectopic bud activity. Further studies indicated that auxin played a key role in inhibiting bud outgrowth in 'Dugan' fir. During bud dormancy release, the differential auxin resistant 1/Like AUX1 (AUX1/LAX) and PIN-formed (PIN) activity resulted in an ectopic auxin/indole-3-acetic acid (IAA) accumulation in the apical shoot stem of 'Dugan' fir, which could inhibit the cell cycle in the axillary meristem by decreasing cytokinin (CK) biosynthesis but increasing abscisic acid (ABA) production and response through the signaling pathway. In contrast, during bud activation and outgrowth, the striking increase in auxin biosynthesis and PIN activity in the shoot tip of 'Dugan' fir may trigger the correlative inhibition of axillary buds by modulating the polar auxin transport stream (PATS) and connective auxin transport (CAT) in shoots, and by influencing the biosynthesis of secondary messengers, including CK, gibberellin (GA) and ABA, thereby inducing the paradormancy of axillary buds in 'Dugan' fir by apical dominance under favorable conditions. The findings of this study provide important insights into the roles of plant hormones in bud outgrowth control in perennial woody plants.
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Affiliation(s)
- Liwei Yang
- Department of Forest Genetics & Biotechnology, Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, No.159 Longpan Road, Nanjing, Jiangsu 210037, China
| | - Sheng Zhu
- Department of Forest Genetics & Biotechnology, Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, No.159 Longpan Road, Nanjing, Jiangsu 210037, China
- Department of Molecular Biology and Biochemistry, College of Biology and Environment, Nanjing Forestry University, No.159 Longpan Road, Nanjing, Jiangsu 210037, China
| | - Jin Xu
- Department of Forest Genetics & Biotechnology, Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, No.159 Longpan Road, Nanjing, Jiangsu 210037, China
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Ma J, Xie L, Zhao Q, Sun Y, Zhang D. Cyclanilide Induces Lateral Bud Outgrowth by Modulating Cytokinin Biosynthesis and Signalling Pathways in Apple Identified via Transcriptome Analysis. Int J Mol Sci 2022; 23:ijms23020581. [PMID: 35054767 PMCID: PMC8776233 DOI: 10.3390/ijms23020581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/31/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
Cyclanilide (CYC), a plant growth regulator, is a potent shoot branching agent in apple. However, its mechanism remains unclear. The current study revealed that CYC treatment resulted in massive reprogramming of the axillary bud transcriptome, implicating several hormones in the response. We observed a marked increase (approximately 2-fold) in the level of zeatin riboside and a significant decrease (approximately 2-fold) in the level of abscisic acid (ABA). Zeatin metabolism gene cytokinin (CTK) oxidase 1 (CKX 1) was down-regulated at 168 h after CYC treatment compared with the control. Weighted gene co-expression network analysis of differentially expressed genes demonstrated the turquoise module clusters exhibited the highest positive correlation with zeatin riboside (r = 0.92) and the highest negative correlation with ABA (r = -0.8). A total of 37 genes were significantly enriched in the plant hormone signal transduction pathway in the turquoise module. Among them, the expressions of CTK receptor genes WOODEN LEG and the CTK type-A response regulators genes ARR3 and ARR9 were up-regulated. ABA signal response genes protein phosphatase 2C genes ABI2 and ABI5 were down-regulated in lateral buds after CYC treatment at 168 h. In addition, exogenous application of 6-benzylaminopurine (6-BA, a synthetic type of CTK) and CYC enhanced the inducing effect of CYC, whereas exogenous application of lovastatin (a synthetic type of inhibitor of CTK biosynthesis) or ABA and CYC weakened the promoting effect of CYC. These results collectively revealed that the stimulation of bud growth by CYC might involve CTK biosynthesis and signalling, including genes CKX1 and ARR3/9, which provided a direction for further study of the branching promoting mechanism of CYC.
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Affiliation(s)
| | | | | | | | - Dong Zhang
- Correspondence: ; Tel./Fax: +86-029-87082849
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Luo Z, Janssen BJ, Snowden KC. The molecular and genetic regulation of shoot branching. PLANT PHYSIOLOGY 2021; 187:1033-1044. [PMID: 33616657 PMCID: PMC8566252 DOI: 10.1093/plphys/kiab071] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/22/2021] [Indexed: 05/27/2023]
Abstract
The architecture of flowering plants exhibits both phenotypic diversity and plasticity, determined, in part, by the number and activity of axillary meristems and, in part, by the growth characteristics of the branches that develop from the axillary buds. The plasticity of shoot branching results from a combination of various intrinsic and genetic elements, such as number and position of nodes and type of growth phase, as well as environmental signals such as nutrient availability, light characteristics, and temperature (Napoli et al., 1998; Bennett and Leyser, 2006; Janssen et al., 2014; Teichmann and Muhr, 2015; Ueda and Yanagisawa, 2019). Axillary meristem initiation and axillary bud outgrowth are controlled by a complex and interconnected regulatory network. Although many of the genes and hormones that modulate branching patterns have been discovered and characterized through genetic and biochemical studies, there are still many gaps in our understanding of the control mechanisms at play. In this review, we will summarize our current knowledge of the control of axillary meristem initiation and outgrowth into a branch.
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Affiliation(s)
- Zhiwei Luo
- The New Zealand Institute for Plant and Food Research Limited, Auckland 1025, New Zealand
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Bart J Janssen
- The New Zealand Institute for Plant and Food Research Limited, Auckland 1025, New Zealand
| | - Kimberley C Snowden
- The New Zealand Institute for Plant and Food Research Limited, Auckland 1025, New Zealand
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Li G, Tan M, Ma J, Cheng F, Li K, Liu X, Zhao C, Zhang D, Xing L, Ren X, Han M, An N. Molecular mechanism of MdWUS2-MdTCP12 interaction in mediating cytokinin signaling to control axillary bud outgrowth. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4822-4838. [PMID: 34113976 DOI: 10.1093/jxb/erab163] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/08/2021] [Indexed: 05/25/2023]
Abstract
Shoot branching is an important factor that influences the architecture of apple trees and cytokinin is known to promote axillary bud outgrowth. The cultivar 'Fuji', which is grown on ~75% of the apple-producing area in China, exhibits poor natural branching. The TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) family genes BRANCHED1/2 (BRC1/2) are involved in integrating diverse factors that function locally to inhibit shoot branching; however, the molecular mechanism underlying the cytokinin-mediated promotion of branching that involves the repression of BRC1/2 remains unclear. In this study, we found that apple WUSCHEL2 (MdWUS2), which interacts with the co-repressor TOPLESS-RELATED9 (MdTPR9), is activated by cytokinin and regulates branching by inhibiting the activity of MdTCP12 (a BRC2 homolog). Overexpressing MdWUS2 in Arabidopsis or Nicotiana benthamiana resulted in enhanced branching. Overexpression of MdTCP12 inhibited axillary bud outgrowth in Arabidopsis, indicating that it contributes to the regulation of branching. In addition, we found that MdWUS2 interacted with MdTCP12 in vivo and in vitro and suppressed the ability of MdTCP12 to activate the transcription of its target gene, HOMEOBOX PROTEIN 53b (MdHB53b). Our results therefore suggest that MdWUS2 is involved in the cytokinin-mediated inhibition of MdTCP12 that controls bud outgrowth, and hence provide new insights into the regulation of shoot branching by cytokinin.
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Affiliation(s)
- Guofang Li
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
- College of Horticulture, Hebei Agricultural University, Baoding, Hebei 071001, China
| | - Ming Tan
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
- College of Horticulture, Hebei Agricultural University, Baoding, Hebei 071001, China
| | - Juanjuan Ma
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Fang Cheng
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Ke Li
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Xiaojie Liu
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Caiping Zhao
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Dong Zhang
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Libo Xing
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Xiaolin Ren
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Mingyu Han
- College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Na An
- College of Life Science, Northwest A & F University, Yangling, Shaanxi 712100, China
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Mallet J, Laufs P, Leduc N, Le Gourrierec J. Photocontrol of Axillary Bud Outgrowth by MicroRNAs: Current State-of-the-Art and Novel Perspectives Gained From the Rosebush Model. FRONTIERS IN PLANT SCIENCE 2021; 12:770363. [PMID: 35173747 PMCID: PMC8841825 DOI: 10.3389/fpls.2021.770363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/13/2021] [Indexed: 05/05/2023]
Abstract
Shoot branching is highly dependent on environmental factors. While many species show some light dependence for branching, the rosebush shows a strict requirement for light to allow branching, making this species an excellent model to further understand how light impinges on branching. Here, in the first part, we provide a review of the current understanding of how light may modulate the complex regulatory network of endogenous factors like hormones (SL, IAA, CK, GA, and ABA), nutrients (sugar and nitrogen), and ROS to control branching. We review the regulatory contribution of microRNAs (miRNAs) to branching in different species, highlighting the action of such evolutionarily conserved factors. We underline some possible pathways by which light may modulate miRNA-dependent regulation of branching. In the second part, we exploit the strict light dependence of rosebush for branching to identify putative miRNAs that could contribute to the photocontrol of branching. For this, we first performed a profiling of the miRNAs expressed in early light-induced rosebush buds and next tested whether they were predicted to target recognized regulators of branching. Thus, we identified seven miRNAs (miR156, miR159, miR164, miR166, miR399, miR477, and miR8175) that could target nine genes (CKX1/6, EXPA3, MAX4, CYCD3;1, SUSY, 6PFK, APX1, and RBOHB1). Because these genes are affecting branching through different hormonal or metabolic pathways and because expression of some of these genes is photoregulated, our bioinformatic analysis suggests that miRNAs may trigger a rearrangement of the regulatory network to modulate branching in response to light environment.
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Affiliation(s)
- Julie Mallet
- University of Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers, France
| | - Patrick Laufs
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Nathalie Leduc
- University of Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers, France
| | - José Le Gourrierec
- University of Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers, France
- *Correspondence: José Le Gourrierec,
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Porcher A, Guérin V, Montrichard F, Lebrec A, Lothier J, Vian A. Ascorbate glutathione-dependent H2O2 scavenging is an important process in axillary bud outgrowth in rosebush. ANNALS OF BOTANY 2020; 126:1049-1062. [PMID: 32639526 PMCID: PMC7596375 DOI: 10.1093/aob/mcaa130] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 07/04/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Branching is an important mechanism of plant shape establishment and the direct consequence of axillary bud outgrowth. Recently, hydrogen peroxide (H2O2) metabolism, known to be involved in plant growth and development, has been proposed to contribute to axillary bud outgrowth. However, the involvement of H2O2 in this process remains unclear. METHODS We analysed the content of H2O2 during bud outgrowth and characterized its catabolism, both at the transcriptional level and in terms of its enzymatic activities, using RT-qPCR and spectrophotometric methods, respectively. In addition, we used in vitro culture to characterize the effects of H2O2 application and the reduced glutathione (GSH) synthesis inhibitor l-buthionine sulfoximine (BSO) on bud outgrowth in relation to known molecular markers involved in this process. KEY RESULTS Quiescent buds displayed a high content of H2O2 that declined when bud outgrowth was initiated, as the consequence of an increase in the scavenging activity that is associated with glutathione pathways (ascorbate-glutathione cycle and glutathione biosynthesis); catalase did not appear to be implicated. Modification of bud redox state after the application of H2O2 or BSO prevented axillary bud outgrowth by repressing organogenesis and newly formed axis elongation. Hydrogen peroxide also repressed bud outgrowth-associated marker gene expression. CONCLUSIONS These results show that high levels of H2O2 in buds that are in a quiescent state prevents bud outgrowth. Induction of ascorbate-glutathione pathway scavenging activities results in a strong decrease in H2O2 content in buds, which finally allows bud outgrowth.
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Affiliation(s)
- Alexis Porcher
- Université d’Angers, Agrocampus Ouest, INRAE, UMR IRHS, SFR QuaSaV, Beaucouzé, France
| | - Vincent Guérin
- Université d’Angers, Agrocampus Ouest, INRAE, UMR IRHS, SFR QuaSaV, Beaucouzé, France
| | - Françoise Montrichard
- Université d’Angers, Agrocampus Ouest, INRAE, UMR IRHS, SFR QuaSaV, Beaucouzé, France
| | - Anita Lebrec
- Université d’Angers, Agrocampus Ouest, INRAE, UMR IRHS, SFR QuaSaV, Beaucouzé, France
| | - Jérémy Lothier
- Université d’Angers, Agrocampus Ouest, INRAE, UMR IRHS, SFR QuaSaV, Beaucouzé, France
| | - Alain Vian
- Université d’Angers, Agrocampus Ouest, INRAE, UMR IRHS, SFR QuaSaV, Beaucouzé, France
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11
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Asymmetric distribution of cytokinins determines root hydrotropism in Arabidopsis thaliana. Cell Res 2019; 29:984-993. [PMID: 31601978 PMCID: PMC6951336 DOI: 10.1038/s41422-019-0239-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/05/2019] [Indexed: 11/17/2022] Open
Abstract
The phenomenon of plant root tips sensing moisture gradient in soil and growing towards higher water potential is designated as root hydrotropism, which is critical for plants to survive when water is a limited factor. Molecular mechanisms regulating such a fundamental process, however, are largely unknown. Here we report our identification that cytokinins are key signaling molecules directing root growth orientation in a hydrostimulation (moisture gradient) condition. Lower water potential side of the root tip shows more cytokinin response relative to the higher water potential side. Consequently, two cytokinin downstream type-A response regulators, ARR16 and ARR17, were found to be up-regulated at the lower water potential side, causing increased cell division in the meristem zone, which allows the root to bend towards higher water potential side. Genetic analyses indicated that various cytokinin biosynthesis and signaling mutants, including the arr16 arr17 double mutant, are significantly less responsive to hydrostimulation. Consistently, treatments with chemical inhibitors interfering with either cytokinin biosynthesis or cell division completely abolished root hydrotropic response. Asymmetrically induced expression of ARR16 or ARR17 effectively led to root bending in both wild-type and miz1, a previously known hydrotropism-defective mutant. These data demonstrate that asymmetric cytokinin distribution is a primary determinant governing root hydrotropism.
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12
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Liu S, Mi X, Zhang R, An Y, Zhou Q, Yang T, Xia X, Guo R, Wang X, Wei C. Integrated analysis of miRNAs and their targets reveals that miR319c/TCP2 regulates apical bud burst in tea plant (Camellia sinensis). PLANTA 2019; 250:1111-1129. [PMID: 31172343 DOI: 10.1007/s00425-019-03207-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/01/2019] [Indexed: 05/18/2023]
Abstract
MAIN CONCLUSION The roles of microRNA-mediated epigenetic regulation were highlighted in the bud dormancy-activity cycle, implying that certain differentially expressed miRNAs play crucial roles in apical bud burst, such as csn-miR319c/TCP2. microRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression by targeting mRNA transcripts for cleavage or directing translational inhibition. To investigate whether miRNAs regulate bud dormancy-activation transition in tea plant, which largely affects the yield and price of tea products and adaptability of tea trees, we constructed small RNA libraries from three different periods of bud dormancy-burst transition. Through sequencing analysis, 262 conserved and 83 novel miRNAs were identified, including 118 differentially expressed miRNAs. Quantitative RT-PCR results for randomly selected miRNAs exhibited that our comprehensive analysis is highly reliable and accurate. The content of caffeine increased continuously from the endodormancy bud to flushing bud, and differentially expressed miRNAs coupling with their targets associated with bud burst were identified. Remarkably, csn-miR319c was downregulated significantly from the quiescent bud to burst bud, while its target gene CsnTCP2 (TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTOR 2) displayed opposite expression patterns. Co-transformation experiment in tobacco demonstrated that csn-miR319c can significantly suppress the functions of CsnTCP2. This study on miRNAs and the recognition of target genes could provide new insights into the molecular mechanism of the bud dormancy-activation transition in tea plant.
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Affiliation(s)
- Shengrui Liu
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, China
| | - Xiaozeng Mi
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, China
| | - Ran Zhang
- Tea Research Institution, Anhui Academy of Agricultural Sciences, Huangshang, China
| | - Yanlin An
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, China
| | - Qiying Zhou
- Henan Key Laboratory of Tea Plant Biology, Xinyang Normal University, 237 Nanhu Road, Xinyang, 464000, China
| | - Tianyuan Yang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, China
| | - Xiaobo Xia
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, China
| | - Rui Guo
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, China
| | - Xuewen Wang
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Chaoling Wei
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, China.
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Tan M, Li G, Chen X, Xing L, Ma J, Zhang D, Ge H, Han M, Sha G, An N. Role of Cytokinin, Strigolactone, and Auxin Export on Outgrowth of Axillary Buds in Apple. FRONTIERS IN PLANT SCIENCE 2019; 10:616. [PMID: 31156679 PMCID: PMC6530649 DOI: 10.3389/fpls.2019.00616] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 04/25/2019] [Indexed: 05/04/2023]
Abstract
Shoot branching is regulated by phytohormones, including cytokinin (CK), strigolactone (SL), and auxin in axillary buds. The correlative importance of these phytohormones in the outgrowth of apple axillary buds remains unclear. In this study, the outgrowth dynamics of axillary buds of a more-branching mutant (MB) and its wild-type (WT) of Malus spectabilis were assessed using exogenous chemical treatments, transcriptome analysis, paraffin section, and reverse transcription-quantitative PCR analysis (RT-qPCR). High contents of CK and abscisic acid coincided in MB axillary buds. Exogenous CK promoted axillary bud outgrowth in the WT but not in MB, whereas exogenous gibberellic had no significant effect on bud outgrowth in the WT. Functional analysis of transcriptome data and RT-qPCR analysis of gene transcripts revealed that MB branching were associated with CK signaling, auxin transport, and SL signaling. Transcription of the SL-related genes MsMAX1, MsD14, and MsMAX2 in the axillary buds of MB was generally upregulated during bud outgrowth, whereas MsBRC1/2 were generally downregulated both in WT and MB. Exogenous SL inhibited outgrowth of axillary buds in the WT and the apple varieties T337, M26, and Nagafu 2, whereas axillary buds of the MB were insensitive to SL treatment. Treatment with N-1-naphthylphalamic acid (NPA; an auxin transport inhibitor) inhibited bud outgrowth in plants of the WT and MB. The transcript abundance of MsPIN1 was generally decreased in response to NPA and SL treatments, and increased in CK and decapitation treatments, whereas no consistent pattern was observed for MsD14 and MsMAX2. Collectively, the present results suggest that in apple auxin transport from the axillary bud to the stem may be essential for the outgrowth of axillary buds, and at least, is involved in the process of bud outgrowth.
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Affiliation(s)
- Ming Tan
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Guofang Li
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Xilong Chen
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Libo Xing
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Juanjuan Ma
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Dong Zhang
- College of Horticulture, Northwest A&F University, Yangling, China
| | - HongJuan Ge
- Institute of Agricultural Science, Qingdao, China
| | - Mingyu Han
- College of Horticulture, Northwest A&F University, Yangling, China
| | - Guangli Sha
- Institute of Agricultural Science, Qingdao, China
| | - Na An
- College of Life Science, Northwest A&F University, Yangling, China
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