AUTHOR=Zhang Yijin , Liu Xiong , Su Rui , Xiao Yunhua , Deng Huabing , Lu Xuedan , Wang Feng , Chen Guihua , Tang Wenbang , Zhang Guilian 

TITLE=9-cis-epoxycarotenoid dioxygenase 1 confers heat stress tolerance in rice seedling plants

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1092630

DOI=10.3389/fpls.2022.1092630

ISSN=1664-462X

ABSTRACT=<p>High temperature is one of the main constraints affecting plant growth and development. It has been reported that abscisic acid (ABA) synthesis gene <italic>9-cis-epoxycarotenoid dioxygenase</italic> (<italic>NCED</italic>) positively regulates plant resistance to salt, cold, and drought stresses. However, little is known about the function of the <italic>NCED</italic> gene in heat tolerance of rice. Here, we found that <italic>OsNCED1</italic> was a heat stress inducible gene. Rice seedlings overexpressing <italic>OsNCED1</italic> showed enhanced heat tolerance with more abundant ABA content, whereas the knockout mutant <italic>osnced1</italic> accumulated less ABA and showed more sensitive to heat stress. Under heat stress, increased expression of <italic>OsNCED1</italic> could reduce membrane damage and reactive oxygen species (ROS) level of plants, and elevate the activity of antioxidant enzymes. Moreover, real time-quantitative PCR (RT-qPCR) analysis showed that overexpression of <italic>OsNCED1</italic> significantly activated the expression of genes involved in antioxidant enzymes, ABA signaling pathway, heat response, and defense. Together, our results indicate that <italic>OsNCED1</italic> positively regulates heat tolerance of rice seedling by raising endogenous ABA contents, which leads to the improved antioxidant capacity and activated expression of heat and ABA related genes.</p>