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Article|01 Apr 2021|OPEN
Silencing MdGH3-2/12 in apple reduces drought resistance by regulating AM colonization
Dong Huang1, Qian Wang1, Zhijun Zhang1, Guangquan Jing1, Mengnan Ma1, Fengwang Ma1, & Chao Li1,
1State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A & F University, Yangling 712100 Shaanxi, China

Horticulture Research 8,
Article number: 84 (2021)
doi: 10.1038/hortres.2021.84
Views: 256

Received: 25 Aug 2020
Revised: 24 Dec 2020
Accepted: 06 Feb 2021
Published online: 01 Apr 2021

Abstract

Drought leads to reductions in plant growth and crop yields. Arbuscular mycorrhizal fungi (AMF), which form symbioses with the roots of the most important crop species, alleviate drought stress in plants. In the present work, we identified 14 GH3 genes in apple (Malus domestica) and provided evidence that MdGH3-2 and MdGH3-12 play important roles during AM symbiosis. The expression of both MdGH3-2 and MdGH3-12 was upregulated during mycorrhization, and the silencing of MdGH3-2/12 had a negative impact on AM colonization. MdGH3-2/12 silencing resulted in the downregulation of five genes involved in strigolactone synthesis, and there was a corresponding change in root strigolactone content. Furthermore, we observed lower root dry weights in RNAi lines under AM inoculation conditions. Mycorrhizal transgenic plants showed greater sensitivity to drought stress than WT, as indicated by their higher relative electrolytic leakage and lower relative water contents, osmotic adjustment ability, ROS scavenging ability, photosynthetic capacity, chlorophyll fluorescence values, and abscisic acid contents. Taken together, these data demonstrate that MdGH3-2/12 plays an important role in AM symbiosis and drought stress tolerance in apple.