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Article|19 Sep 2023|OPEN
PbrChiA: a key chitinase of pear in response to Botryosphaeria dothidea infection by interacting with PbrLYK1b2 and down-regulating ROS accumulation
Qiming Chen1 ,† , Huizhen Dong1 ,† , Qionghou Li1 , Xun Sun1 , Xin Qiao1 , Hao Yin1 , Zhihua Xie1 , Kaijie Qi1 , Xiaosan Huang1 , and Shaoling Zhang,1 ,
1State Key Laboratory of Crop Genetics and Germplasm Enhancement, Centre of Pear Engineering Technology Research, Nanjing Agricultural University, Nanjing 210095, China
*Corresponding author. E-mail:,
Both authors contributed equally to the study.

Horticulture Research 10,
Article number: uhad188 (2023)
Views: 110

Received: 24 May 2023
Accepted: 07 Sep 2023
Published online: 19 Sep 2023


Pear ring rot, caused by the pathogenic fungi Botryosphaeria dothidea, seriously affects pear production. While the infection-induced reactive oxygen species (ROS) burst of infected plants limits the proliferation of B. dothidea during the early infection stage, high ROS levels can also contribute to their growth during the later necrotrophic infection stage. Therefore, it is important to understand how plants balance ROS levels and resistance to pathogenic B. dothidea during the later stage. In this study, we identified PbrChiA, a glycosyl hydrolases 18 (GH18) chitinase-encoding gene with high infection-induced expression, through a comparative transcriptome analysis. Artificial substitution, stable overexpression, and virus induced gene silencing (VIGS) experiments demonstrated that PbrChiA can positively regulate pear resistance as a secreted chitinase to break down B. dothidea mycelium in vitro and that overexpression of PbrChiA suppressed infection-induced ROS accumulation. Further analysis revealed that PbrChiA can bind to the ectodomain of PbrLYK1b2, and this interaction suppressed PbrLYK1b2-mediated chitin-induced ROS accumulation. Collectively, we propose that the combination of higher antifungal activity from abundant PbrChiA and lower ROS levels during later necrotrophic infection stage confer resistance of pear against B. dothidea.