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Article|01 Nov 2018|OPEN
Overexpression of MdATG18a in apple improves resistance to Diplocarpon mali infection by enhancing antioxidant activity and salicylic acid levels
Xun Sun1, Liuqing Huo1, Xin Jia1, Runmin Che1, Xiaoqing Gong1, Ping Wang1 & Fengwang Ma1,
1State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, 712100 Yangling, Shaanxi, China

Horticulture Research 5,
Article number: 57 (2018)
doi: 10.1038/hortres.2018.57
Views: 661

Received: 08 Jan 2018
Revised: 04 Jun 2018
Accepted: 04 Jun 2018
Published online: 01 Nov 2018

Abstract

Marssonina apple blotch, caused by Diplocarpon mali, is one of the most serious diseases of apple. Autophagy plays a key role in pathogen resistance. We previously showed that MdATG18a has a positive influence on drought tolerance. Herein, we describe how overexpression (OE) of MdATG18a enhances resistance to D. mali infection, probably because less H2O2 but more salicylic acid (SA) is accumulated in the leaves of OE apple plants. Expression of chitinase, β-1,3-glucanase, and SA-related marker genes was induced more strongly by D. mali in OE lines. Transcript levels of other important MdATG genes were also drastically increased by D. mali in OE plants, which indicated increased autophagy activities. Taken together, these results demonstrate that OE of MdATG18a enhances resistance to infection by D. mali and plays positive roles in H2O2-scavenging and SA accumulations. Our findings provide important information for designing strategies which could induce autophagy to minimize the impact of this disease on apple production.