Arabidopsis Zinc Finger 3 is regulated by heat shock factors and acts as a repressor in response to heat stress

• Main Authors: Yu-Jen Chen, 陳昱仁
• Other Authors: 靳宗洛
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/p5g68q

碩士 === 國立臺灣大學 === 植物科學研究所 === 105 === Heat stress (HS) refers to temperatures above the optimum growth temperatures for organisms. This stress can lead plants to experience severe retardation in growth and development, and in extreme cases cause death. In order to survive, a conserved mechanism of heat stress responses (HSR) is developed to accumulate heat shock proteins (HSPs) to protect plants via a group of transcription factors called heat shock factors (HSFs). In our previous study, we reported that a special Arabidopsis HSF HSFA6b regulates the HSR via the ABA-dependent pathway. In the heat response microarray data, we detected a zinc protein transcription factor Zinc Finger 3 (ZF3) which was suggested to be regulated under HSFA6b. Here, we describe the regulation and function of ZF3 under HS. Our investigation shows that the expression of ZF3 is induced by heat stress and ZF3 is localized to the nucleus. ZF3 regulation is influenced by the complex network of HSFs; our data shows that ZF3 is strongly regulated by HSFA3 and HSFA6b while other HSFs such as HSFA1b may also influence the regulation of ZF3 via the DREB-HSFA3 pathway. In addition, ZF3 knockout mutants displayed increased thermotolerance as compared with the WT for acquired thermotolerance; this indicated that ZF3 is a repressor in HSR. Further investigation of gene expression showed that ZF3 can repress the expression of sHSPs and of antioxidant gene APX2. Thus, we report that ZF3 is a heat induced transcription factor that was confirmed to be localized in the nucleus, and functions as a HSR negative regulator in Arabidopsis.