ABA Regulates Subcellular Redistribution of OsABI-LIKE2, a Negative Regulator in ABA Signaling, to Control Root Architecture and Drought Resistance in Oryza sativa.
The phytohormone ABA is a key stress signal in plants. Although the identification of ABA receptors led to significant progress in understanding the Arabidopsis ABA signaling pathway, there are still many unsolved mysteries regarding ABA signaling in monocots, such as rice. Here, we report that a rice ortholog of AtABI1 and AtABI2, named OsABI-LIKE2 (OsABIL2), plays a negative role in rice ABA signaling. Overexpression of OsABIL2 not only led to ABA insensitivity, but also significantly altered plant developmental phenotypes, including stomatal density and root architecture, which probably caused the hypersensitivity to drought stress. OsABIL2 interacts with OsPYL1, SAPK8 and SAPK10 both in vitro and in vivo, and the phosphatase activity of OsABIL2 was repressed by ABA-bound OsPYL1. However, unlike many other solely nuclear-localized clade A type 2C protein phosphatases (PP2Cs), OsABIL2 is localized in both the nucleus and cytosol. Furthermore, OsABIL2 interacts with and co-localized with OsPYL1 mainly in the cytosol, and ABA treatment regulates the nucleus-cytosol distribution of OsABIL2, suggesting a different mechanism for the activation of ABA signaling. Taken together, this study provides significant insights into rice ABA signaling and indicates the important role of OsABIL2 in regulating root development.
National Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
Chengxiang
C
Li
National Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
Hongyun
H
Shen
National Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China National Key Laboratory of Crop Genetic Improvement, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
Tao
T
Wang
National Key Laboratory of Crop Genetic Improvement, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China xlwang@mail.hzau.edu.cn.
Xuelu
X
Wang
D000040:Abscisic Acid / Q000494:pharmacology*; D055864:Droughts; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D025461:Feedback, Physiological; D012275:Oryza / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D010940:Plant Proteins / Q000378:metabolism*; D018517:Plant Roots / Q000033:anatomy & histology* / Q000187:drug effects / Q000378:metabolism; D018526:Plant Transpiration / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects*; D013347:Subcellular Fractions / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D010940:Plant Proteins; D000040:Abscisic Acid
ABA; Clade A type 2C protein phosphatase; Drought resistance; Oryza sativa; OsABIL2; Root architecture; Subcellular redistribution