MdZAT5 regulates drought tolerance via mediating accumulation of drought‐responsive miRNAs and mRNAs in apple

Abstract

Summary Drought limits apple yield and fruit quality. However, the molecular mechanism of apple in response to drought is not well known. Here, we report a Cys2/His2 (C2H2)‐type zinc‐finger protein, MdZAT5, that positively regulates apple drought tolerance by regulating drought‐responsive RNAs and microRNAs (miRNAs). DNA affinity purification and sequencing and yeast‐one hybrid analysis identified the binding motifs of MdZAT5, T/ACACT/AC/A/G. Chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP‐qPCR) and electrophoretic mobility shift assays (EMSAs) showed that MdZAT5 directly binds to the promoters of the drought‐responsive genes including MdRHA2a, MdLEA14, MdTPX1, and MdCAT3, and activates their expression under drought stress. MdZAT5 interacts with and directly targets HYPONASTIC LEAVES1 (MdHYL1). MdZAT5 may facilitate the interaction of MdHYL1 with pri‐miRNAs or MdDCL1 by activating MdHYL1 expression, thereby regulating the biogenesis of drought‐responsive miRNAs. Genetic dissection showed that MdHYL1 is essential for MdZAT5‐mediated drought tolerance and miRNA biogenesis. In addition, ChIP‐qPCR and EMSA revealed that MdZAT5 binds directly to the promoters of some MIR genes including Mdm‐miR171i and Mdm‐miR172c, and modulates their transcription. Taken together, our findings improve our understanding of the molecular mechanisms of drought response in apple and provide a candidate gene for the breeding of drought‐tolerant cultivars.

Surviving a Double-Edged Sword: Response of Horticultural Crops to Multiple Abiotic Stressors

“…For instance, pre-mRNA alternative splicing can modulate the responses of tomato against high-temperature stress [165]. The Cys2/His2 (C2H2)-type zinc finger protein MdZAT5 targets drought-responsive RNAs and microR-NAs to control apple's tolerance to drought [166].…”

Apple Glycosyltransferase MdUGT73AR4 Glycosylates ABA to Regulate Stomatal Movement Involved in Drought Stress

“…As the world’s largest producer and consumer of apples, China accounts for more than 40% of the world’s apple cultivation area and production, and it is important to give full play to the advantages of China’s apple industry in order to increase the income of the plantation industry [ 1 ]. Since apple production areas are mostly located in arid and semi-arid regions, such as the Loess Plateau, the Bohai Bay, the old course of the Yellow River, and the cool highlands in southwest China, drought has become a major constraint on the growth and development of apples, which seriously affects the sustainable development of the apple industry [ 2 ]. Therefore, understanding the drought stress response mechanism of apples is crucial for the apple-growing industry.…”

A C2H2‐type zinc finger protein ZAT12 of Poncirus trifoliata acts downstream of CBF1 to regulate cold tolerance

“…Unlike the animal counterparts, most plant zinc finger proteins contain one or two QALGGH motifs, which play a key role in DNA‐binding activity (Feng et al., 2023; Pabo et al., 2001). Emerging evidence indicates that the C2H2‐type zinc finger proteins are implicated in plant responses to various stresses (Bao et al., 2022; Ciftci‐Yilmaz et al., 2007; Li et al., 2018). For instance, ZAT10 and ZAT12 of Arabidopsis thaliana can respond to different environmental stimuli, such as cold, drought, salt, and oxidative stress (Daniel et al., 2016; Davletova et al., 2005; Hichri et al., 2014; Mittler et al., 2006; Vogel et al., 2005).…”