ROP11 GTPase is a negative regulator of multiple ABA responses in Arabidopsis.
The phytohormone abscisic acid (ABA) plays crucial roles in plant development and plant responses to environmental stresses. Although ABA receptors and a minimal set of core molecular components have recently been discovered, understanding of the ABA signaling pathway is still far from complete. In this work, we characterized the function of ROP11, a member of the plant-specific ROP small GTPases family, in the ABA signaling process. ROP11 is preferentially expressed in guard cells in all plant organs with stomata. Expression of a constitutively active ROP11 (CA-ROP11) suppresses ABA-mediated responses, whereas reduced expression of ROP11 or expression of its dominant-negative form (DN-ROP11) causes the opposite phenotypes. The affected ABA-mediated responses by ROP11 include seed germination, seedling growth, stomatal closure, induction of ABA-responsive genes, as well as plant response to drought stress. Furthermore, we showed that ROP11 and its closest-related family member, ROP10, act in parallel in mediating these responses. ABA treatment does not affect ROP11 transcription and protein abundance; however, it causes the accumulation of CA-ROP11 in the nucleus. These results demonstrated that ROP11 is a negative regulator of multiple ABA responses in Arabidopsis.
MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Zixing
Z
Li
Jun
J
Kang
Ning
N
Sui
Dong
D
Liu
D000040:Abscisic Acid / Q000494:pharmacology*; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D055864:Droughts; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D054046:Plant Stomata / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D014158:Transcription, Genetic / Q000187:drug effects; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D000040:Abscisic Acid; D019204:GTP-Binding Proteins; C472133:ROP10 protein, Arabidopsis; C572957:ROP11 protein, Arabidopsis; D020741:rho GTP-Binding Proteins