Related Experiment Video
Updated: Oct 22, 2025

Measuring Gene Expression in Bombarded Barley Aleurone Layers with Increased Throughput
Published on: March 30, 2018
Arabidopsis SIGMA FACTOR BINDING PROTEIN1 (SIB1) and SIB2 inhibit WRKY75 function in abscisic acid-mediated leaf
Haiyan Zhang1,2, Liping Zhang1,3, Yunrui Ji1,2
1CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China.
Abstract:
The plant-specific VQ gene family participates in diverse physiological processes but little information is available on their role in leaf senescence. Here, we show that the VQ motif-containing proteins, Arabidopsis SIGMA FACTOR BINDING PROTEIN1 (SIB1) and SIB2 are negative regulators of abscisic acid (ABA)-mediated leaf senescence. Loss of SIB1 and SIB2 function resulted in increased sensitivity of ABA-induced leaf senescence. In contrast, overexpression of SIB1 significantly delayed this process. Moreover, biochemical studies revealed that SIBs interact with WRKY75 transcription factor. Loss of WRKY75 function decreased sensitivity to ABA-induced leaf senescence, while overexpression of WRKY75 significantly accelerated this process. Chromatin immunoprecipitation assays revealed that WRKY75 directly binds to the promoters of GOLDEN 2-LIKE1(GLK1) and GLK2, to repress their expression. SIBs repress the transcriptional function of WRKY75 and negatively regulate ABA-induced leaf senescence in a WRKY75-dependent manner. In contrast, WRKY75 positively modulates ABA-mediated leaf senescence in a GLK-dependent manner. In addition, SIBs inhibit WRKY75 function in ABA-mediated seed germination. These results demonstrate that SIBs can form a complex with WRKY75 to regulate ABA-mediated leaf senescence and seed germination.
More Related Videos
08:52A Seed Coat Bedding Assay to Genetically Explore In Vitro How the Endosperm Controls Seed Germination in Arabidopsis thaliana
Published on: November 9, 2013
06:28Preparation of Intact Tissue for Microscopic Analysis of the Endosperm Cell Layer in Developing and Mature Arabidopsis Seeds
Published on: May 16, 2025
Related Concept Videos
Cell Signaling in Plants
Adaptations that Reduce Water Loss
Gene Regulation During Sporulation
Riboswitches
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...