AUTHOR=Xiao Xiaorong , Wang Rui , Khaskhali Shahneela , Gao Zhiliang , Guo Wenya , Wang Honggang , Niu Xiaolei , He Chaoze , Yu Xiaohui , Chen Yinhua 

TITLE=A Novel Glycerol Kinase Gene OsNHO1 Regulates Resistance to Bacterial Blight and Blast Diseases in Rice

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.800625

DOI=10.3389/fpls.2021.800625

ISSN=1664-462X

ABSTRACT=<p>Glycerol-induced resistance to various pathogens has been reported in different plants. Glycerol kinase (GK), a vital rate-limiting enzyme that catalyzes glycerol conversion to glycerol-3-phosphate (G3P), participates in responses to both abiotic and biotic stresses. However, its physiological importance in rice defenses against pathogens remains unclear. In this research, quantification analysis revealed that GK levels were significantly induced in rice leaves infected by <italic>Xanthomonas oryzae</italic> pv. <italic>oryzae (Xoo)</italic> strain PXO99. A typical GK-encoding gene <italic>OsNHO1</italic> was cloned in rice. The transcriptional levels of <italic>OsNHO1</italic> were significantly induced by salicylic acid, jasmonic acid, and <italic>Xoo-</italic>PXO99. Ectopic expression of <italic>OsNHO1</italic> partially rescued the resistance to <italic>P. s. pv. phaseolicola</italic> in the <italic>Arabidopsis nho1</italic> mutant. In the overexpressing transgenic rice lines (<italic>OsNHO1</italic>-OE), the content of GK and the transcriptional level of <italic>OsNHO1</italic> were increased and the resistance to bacterial blight and blast was improved, while reduced <italic>OsNHO1</italic> expression impaired the resistance in <italic>OsNHO1</italic>-RNAi lines. The wax contents and expression of the wax synthesis regulatory genes were significantly increased in the overexpression lines but decreased in the <italic>OsNHO1</italic>-RNAi lines. We then confirmed the interaction partner of OsNHO1 using yeast two-hybrid and bimolecular fluorescence complementation assays. The transcription of the interaction partner-encoding genes <italic>OsSRC2</italic> and <italic>OsPRs</italic> in <italic>OsNHO1</italic>-RNAi lines was downregulated but upregulated in <italic>OsNHO1</italic>-OE lines. Thus, we concluded that <italic>OsNHO1</italic> provided disease resistance by affecting the wax content and modulating the transcription levels of <italic>PR</italic> genes.</p>