Dissecting Abscisic Acid Signaling Pathways Involved in Cuticle Formation  

作　　者：Fuqiang Cui Mikael Brosche Mikko T. Lehtonen Ali Amiryousefi Enjun Xu Matleena Punkkinen Jari P.T. Valkonen Hiroaki Fujii Kirk Overmyer 

机构地区：[1]Division of Plant Biology, Viikki Plant Science Centre, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland [2]Department of Agricultural Sciences, University of Helsinki, PO Box 27, 00014 Helsinki, Finland [3]Department of Biochemistry, Molecular Plant Biology, University of Turku, Turku 20014, Finland [4]Institute of Technology, University of Tartu, Nooruse 1, Tartu 50411, Estonia [5]Present address: Institute of Botany, The Chinese Academy of Sciences, Beijing, China

出　　处：《Molecular Plant》2016年第6期926-938,共13页分子植物（英文版）

摘　　要：The cuticle is the outer physical barrier of aerial plant surfaces and an important interaction point between plants and the environment. Many environmental stresses affect cuticle formation, yet the regulatory pathways involved remain undefined. We used a genetics and gene expression analysis in Arabidopsis thaliana to define an abscisic acid （ABA） signaling loop that positively regulates cuticle formation via the core ABA signaling pathway, including the PYR/PYL receptors, PP2C phosphatase, and SNF1-Related Protein Kinase （SnRK） 2.21SnRK2.3/SnRK2.6. Downstream of the SnRK2 kinases, cuticle formation was not regulated by the ABA-responsive element-binding transcription factors but rather by DEWAX, MYB16, MYB94, and MYB96. Additionally, low air humidity increased cuticle formation independent of the core ABA pathway and cell death/reactive oxygen species signaling attenuated expression of cuticle-biosynthesis genes. In Physcornitrella patens, exogenous ABA suppressed expression of cuticle- related genes, whose Arabidopsis orthologs were ABA-induced. Hence, the mechanisms regulating cuticle formation are conserved but sophisticated in land plants. Signaling specifically related to cuticle deficiency was identified to play a major role in the adaptation of ABA signaling pathway mutants to increased humidity and in modulating their immunity to Botrytis cinerea in Arabidopsis. These results define a cuticle-specific downstream branch in the ABA signaling pathway that regulates responses to the external environment.The cuticle is the outer physical barrier of aerial plant surfaces and an important interaction point between plants and the environment. Many environmental stresses affect cuticle formation, yet the regulatory pathways involved remain undefined. We used a genetics and gene expression analysis in Arabidopsis thaliana to define an abscisic acid （ABA） signaling loop that positively regulates cuticle formation via the core ABA signaling pathway, including the PYR/PYL receptors, PP2C phosphatase, and SNF1-Related Protein Kinase （SnRK） 2.21SnRK2.3/SnRK2.6. Downstream of the SnRK2 kinases, cuticle formation was not regulated by the ABA-responsive element-binding transcription factors but rather by DEWAX, MYB16, MYB94, and MYB96. Additionally, low air humidity increased cuticle formation independent of the core ABA pathway and cell death/reactive oxygen species signaling attenuated expression of cuticle-biosynthesis genes. In Physcornitrella patens, exogenous ABA suppressed expression of cuticle- related genes, whose Arabidopsis orthologs were ABA-induced. Hence, the mechanisms regulating cuticle formation are conserved but sophisticated in land plants. Signaling specifically related to cuticle deficiency was identified to play a major role in the adaptation of ABA signaling pathway mutants to increased humidity and in modulating their immunity to Botrytis cinerea in Arabidopsis. These results define a cuticle-specific downstream branch in the ABA signaling pathway that regulates responses to the external environment.

关 键 词：cuticle abscisic acid ARABIDOPSIS PHYSCOMITRELLA BOTRYTIS land plants 

分 类 号：Q257[生物学—细胞生物学] TS974.1[轻工技术与工程]