AUTHOR=Xiong Jie , Tao Tao , Luo Zhi , Yan Shuaigang , Liu Yi , Yu Xinqiao , Liu Guolan , Xia Hui , Luo Lijun 

TITLE=RNA Editing Responses to Oxidative Stress between a Wild Abortive Type Male-Sterile Line and Its Maintainer Line

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.02023

DOI=10.3389/fpls.2017.02023

ISSN=1664-462X

ABSTRACT=<p>RNA editing of mitochondrial gene transcripts plays a central role during plant development and evolutionary adaptation. RNA editing has previously been reported to differ between the rice cytoplasmic male sterile (CMS) line and its maintainer line, which has been suggested as a cause for their different performances under environmental stress. To specifically test this hypothesis, a wild abortive (WA) CMS line (Huhan-1A) and its maintainer line (Huhan-1B) were utilized to investigate performances in response to oxidative stress, as well as RNA editing efficiencies on transcripts of six selected mitochondrial genes. Compared to the maintainer line, Huhan-1A represented both lower plant height and total antioxidant capacity, possessed higher total soluble protein and chlorophyll contents, accumulated less H<sub>2</sub>O<sub>2</sub> content on the 3rd day after treatment (DAT), and exhibited higher survival ratio after re-watering. Furthermore, a total of 90 editing sites were detected on transcripts of six mitochondrial genes (<italic>atp9, nad2, nad7, nad9, ccmB</italic>, and <italic>ccmC</italic>) in both Huhan-1A and Huhan-1B on the 0, 1st, and 3rd DAT. Forty-eight sites were furthermore determined as stress-responsive sites (SRS). Generally, in response to oxidative stress, SRS in Huhan-1A increased the resulting editing efficiencies, while SRS in Huhan-1B decreased the resulting editing efficiencies. In addition, 33 and 22 sites at <italic>ccmB</italic> and <italic>ccmC</italic> were differentially edited between Huhan-1A and Huhan-1B, respectively, on the 0, 1st, and 3rd DAT. Editing efficiencies of <italic>ccmB</italic> and <italic>ccmC</italic> were generally lower in Huhan-1A (<italic>ccmB</italic>, 37.3–47.8%; <italic>ccmC</italic>, 41.2–52.3%) than those in Huhan-1B (<italic>ccmB</italic>, 82.6–86.5%; <italic>ccmC</italic>, 81.0–82.9%). Deficiencies of RNA editing in Huhan-1A at <italic>ccmB</italic> and <italic>ccmC</italic> could lead to the loss of transmembrane domains in their protein structures. Consequently, differences in RNA editing at <italic>ccmB</italic> and <italic>ccmC</italic> between the WA-CMS line and its maintainer line partially explained their different performances under stress. Moreover, we detected differences in expressions of pentatricopeptide repeat (PPR) genes between both lines, as well as significant correlations with RNA editing. Our study indicated potential associations of RNA editing and PPR genes in rice tolerance to abiotic stresses. However, the underlying molecular mechanisms of stress-adaptation, which are attributed to RNA editing on transcripts of mitochondrial genes, require further investigation.</p>