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Whirly1 enhances tolerance to chilling stress in tomato via protection of photosystem II and regulation of starch degradation
Author(s) -
Zhuang Kunyang,
Kong Fanying,
Zhang Song,
Meng Chen,
Yang Minmin,
Liu Zhuangbin,
Wang Yong,
Ma Nana,
Meng Qingwei
Publication year - 2019
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.15532
Subject(s) - photosystem ii , degradation (telecommunications) , photosynthesis , starch , chemistry , freezing tolerance , botany , biology , biochemistry , gene , telecommunications , computer science
Summary In plants, the chilling response involves decreased photosynthetic capacity and increased starch accumulation in chloroplasts. However, the mechanisms that modulate these processes remain unclear. We found that the Sl WHY 1 gene is significantly induced by chilling stress (4°C) in tomato. Three Sl WHY 1 overexpression ( OE ) lines grew better than the wild type ( WT ) under chilling stress; the OE plants retained intact photosynthetic grana lamellae and showed enhanced hydrolysis of starch. By contrast, RNA i lines that inhibited Sl WHY 1 were more affected than the corresponding WT cultivar. Their grana lamellae were damaged and starch content increased. The psbA gene encodes the key photosystem II (PSII) protein D1. We show that Sl WHY 1 binds to the upstream region (A/ GTTACCCT /A) of SlpsbA and enhances the de novo synthesis of D1 in chloroplasts. Additionally, Sl WHY 1 regulates the expression of the starch‐degrading enzyme α‐amylase ( Sl AMY 3‐L ) and the starch synthesis‐related enzyme isoamylase gene ( Sl ISA 2 ) in the nucleus, thus modulating the starch content in chloroplasts. We demonstrate that Sl WHY 1 enhances the resistance of tomato to chilling stress by maintaining the function of PSII and degrading starch. Thus, overexpression of WHY 1 may be an effective strategy for enhancing resistance to chilling stress of chilling‐sensitive crops in agricultural production.