10.3389/fpls.2018.00405.s007
Yongxiang Liao
Yongxiang
Liao
Que Bai
Que
Bai
Peizhou Xu
Peizhou
Xu
Tingkai Wu
Tingkai
Wu
Daiming Guo
Daiming
Guo
Yongbin Peng
Yongbin
Peng
Hongyu Zhang
Hongyu
Zhang
Xiaoshu Deng
Xiaoshu
Deng
Xiaoqiong Chen
Xiaoqiong
Chen
Ming Luo
Ming
Luo
Asif Ali
Asif
Ali
Wenming Wang
Wenming
Wang
Xianjun Wu
Xianjun
Wu
Image_7.JPEG
Frontiers
2018
abscisic acid
xanthoxin dehydrogenase
gibberellin
ABA/GA ratio
lesion mimic mutant
pre-harvest sprouting
defense responses
Oryza sativa L.
2018-03-28 04:12:21
Figure
https://frontiersin.figshare.com/articles/figure/Image_7_JPEG/6045545
<p>Lesion mimic mutants display spontaneous cell death, and thus are valuable for understanding the molecular mechanism of cell death and disease resistance. Although a lot of such mutants have been characterized in rice, the relationship between lesion formation and abscisic acid (ABA) synthesis pathway is not reported. In the present study, we identified a rice mutant, lesion mimic mutant 9150 (lmm9150), exhibiting spontaneous cell death, pre-harvest sprouting, enhanced growth, and resistance to rice bacterial and blast diseases. Cell death in the mutant was accompanied with excessive accumulation of H<sub>2</sub>O<sub>2</sub>. Enhanced disease resistance was associated with cell death and upregulation of defense-related genes. Map-based cloning identified a G-to-A point mutation resulting in a D-to-N substitution at the amino acid position 110 of OsABA2 (LOC_Os03g59610) in lmm9150. Knock-out of OsABA2 through CRISPR/Cas9 led to phenotypes similar to those of lmm9150. Consistent with the function of OsABA2 in ABA biosynthesis, ABA level in the lmm9150 mutant was significantly reduced. Moreover, exogenous application of ABA could rescue all the mutant phenotypes of lmm9150. Taken together, our data linked ABA deficiency to cell death and provided insight into the role of ABA in rice disease resistance.</p>