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Zhao B, Liu Q, Wang B, Yuan F. Roles of Phytohormones and Their Signaling Pathways in Leaf Development and Stress Responses. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:3566-3584. [PMID: 33739096 DOI: 10.1021/acs.jafc.0c07908] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Phytohormones participate in various processes over the course of a plant's lifecycle. In addition to the five classical phytohormones (auxins, cytokinins, gibberellins, abscisic acid, and ethylene), phytohormones such as brassinosteroids, jasmonic acid, salicylic acid, strigolactones, and peptides also play important roles in plant growth and stress responses. Given the highly interconnected nature of phytohormones during plant development and stress responses, it is challenging to study the biological function of a single phytohormone in isolation. In the current Review, we describe the combined functions and signaling cascades (especially the shared points and pathways) of various phytohormones in leaf development, in particular, during leaf primordium initiation and the establishment of leaf polarity and leaf morphology as well as leaf development under various stress conditions. We propose a model incorporating the roles of multiple phytohormones in leaf development and stress responses to illustrate the underlying combinatorial signaling pathways. This model provides a reference for breeding stress-resistant crops.
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Affiliation(s)
- Boqing Zhao
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong 250014, P. R. China
| | - Qingyun Liu
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong 250014, P. R. China
| | - Baoshan Wang
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong 250014, P. R. China
| | - Fang Yuan
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, Shandong 250014, P. R. China
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Wang L, Liu J, Shen Y, Pu R, Hou M, Wei Q, Zhang X, Li G, Ren H, Wu G. Brassinosteroids synthesised by CYP85A/A1 but not CYP85A2 function via a BRI1-like receptor but not via BRI1 in Picea abies. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:1748-1763. [PMID: 33247718 DOI: 10.1093/jxb/eraa557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Brassinosteroids (BRs) are essential plant hormones. In angiosperms, brassinolide and castasterone, the first and second most active BRs, respectively, are synthesised by CYP85A2 and CYP85A/A1, respectively. BRs in angiosperms function through an essential receptor, BR Insensitive 1 (BRI1). In addition, some angiosperms also have non-essential BRI1-like 1/3 (BRL1/3). In conifers, BRs promote seed germination under drought stress; however, how BRs function in gymnosperms is unknown. In this study, we performed functional complementation of BR biosynthesis and receptor genes from Picea abies with respective Arabidopsis mutants. We found that P. abies possessed functional PaCYP85A and PaBRL1 but not PaCYP85A2 or PaBRI1, and this results in weak BR signaling, and both PaCYP85A and PaBRL1 were abundantly expressed. However, neither BR treatment of P. abies seedlings nor expression of PaBRL1 in the Arabidopsis Atbri1 mutant promoted plant height, despite the fact that BR-responsive genes were activated. Importantly, chimeric AtBRI1 replaced with the BR-binding domain of PaBRL1 complemented the Atbri1 phenotypes. Furthermore, PaBRL1 had less kinase activity than BRI1 in vitro. Overall, P. abies had weak but still active BR signaling, explaining aspects of its slow growth and high stress tolerance. Our study sheds light on the functional and evolutionary significance of distinct BR signaling that is independent of BRI1 and brassinolide.
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Affiliation(s)
- Li Wang
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Jing Liu
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Yitong Shen
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Ruolan Pu
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Meiying Hou
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Qiang Wei
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Xinzhen Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Guishuang Li
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Hongyan Ren
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
| | - Guang Wu
- College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi Province, P.R. China
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