title: Deletion of an Endoplasmic Reticulum Stress Response Element in a ZmPP2C-A Gene Facilitates Drought Tolerance of Maize Seedlings.
abstract: Drought is a major abiotic stress that causes the yearly yield loss of maize, a crop cultured worldwide. Breeding drought-tolerant maize cultivars is a priority requirement of world agriculture. Clade A PP2C phosphatases (PP2C-A), which are conserved in most plant species, play important roles in abscisic acid (ABA) signaling and plant drought response. However, natural variations of PP2C-A genes that are directly associated with drought tolerance remain to be elucidated. Here, we conducted a candidate gene association analysis of the ZmPP2C-A gene family in a maize panel consisting of 368 varieties collected worldwide, and identified a drought responsive gene ZmPP2C-A10 that is tightly associated with drought tolerance. We found that the degree of drought tolerance of maize cultivars negatively correlates with the expression levels of ZmPP2C-A10. ZmPP2C-A10, like its Arabidopsis orthologs, interacts with ZmPYL ABA receptors and ZmSnRK2 kinases, suggesting that ZmPP2C-A10 is involved in mediating ABA signaling in maize. Transgenic studies in maize and Arabidopsis confirmed that ZmPP2C-A10 functions as a negative regulator of drought tolerance. Further, a causal natural variation, deletion allele-338, which bears a deletion of ERSE (endoplasmic reticulum stress response element) in the 5'-UTR region of ZmPP2C-A10, was detected. This deletion causes the loss of endoplasmic reticulum (ER) stress-induced expression of ZmPP2C-A10, leading to increased plant drought tolerance. Our study provides direct evidence linking ER stress signaling with drought tolerance and genetic resources that can be used directly in breeding drought-tolerant maize cultivars.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Sun
authors.affiliation: College of Plant Science, Tarim University, Alaer 843300, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qin
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: mingqiudai@mail.hzau.edu.cn.
authors.forename: Mingqiu
authors.initials: M
authors.lastname: Dai
mesh_terms: D055864:Droughts; D059865:Endoplasmic Reticulum Stress / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000378:metabolism*; D003313:Zea mays / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins
keywords: ER stress signaling; clade A PP2C; drought response; maize (Zea Mays); natural variation