OsPP2C09, a negative regulatory factor in abscisic acid signalling, plays an essential role in balancing plant growth and drought tolerance in rice

Abstract

Summary Plants maintain a dynamic balance between plant growth and stress tolerance to optimise their fitness and ensure survival. Here, we investigated the roles of a clade A type 2C protein phosphatase (PP2C)‐encoding gene, OsPP2C09, in regulating the trade‐off between plant growth and drought tolerance in rice (Oryza sativa L.). The OsPP2C09 protein interacted with the core components of abscisic acid (ABA) signalling and showed PP2C phosphatase activity in vitro. OsPP2C09 positively affected plant growth but acted as a negative regulator of drought tolerance through ABA signalling. Transcript and protein levels of OsPP2C09 were rapidly induced by exogenous ABA treatments, which suppressed excessive ABA signalling and plant growth arrest. OsPP2C09 transcript levels in roots were much higher than those in shoots under normal conditions. After ABA, polyethylene glycol and dehydration treatments, the accumulation rate of OsPP2C09 transcripts in roots was more rapid and greater than that in shoots. This differential expression between the roots and shoots may increase the plant’s root‐to‐shoot ratio under drought‐stress conditions. This study sheds new light on the roles of OsPP2C09 in coordinating plant growth and drought tolerance. In particular, we propose that OsPP2C09‐mediated ABA desensitisation contributes to root elongation under drought‐stress conditions in rice.

Identification of long noncoding natural antisense transcripts (lncNATs) correlated with drought stress response in wild rice (Oryza nivara)

“…Plants cope with drought stress by regulating phytohormones (such as abscisic acid [ABA], jasmonic acid [JA], and auxin) or making osmotic adjustments [8]. These mechanisms of drought stress response involve genes belonging to various families including WRKY, MYB, NAC, ABRE, PP2C, and SnRK2 [9][10][11][12][13].…”

The Rice Abscisic Acid-Responsive RING Finger E3 Ligase OsRF1 Targets OsPP2C09 for Degradation and Confers Drought and Salinity Tolerance in Rice

“…As we demonstrated that the OsRF1 targets a key repressor of ABA signaling OsPP2C09 ( Figures 6A,B ) and as previous reports indicated that the phosphorylation status was closely correlated with the protein stability of DELLA proteins ( Wang et al, 2009 ; Dai and Xue, 2010 ; Qin et al, 2014 ; Blanco-Tourinan et al, 2020 ), we further investigated the SRL1 protein level in the OsPP2C09-OE transgenic rice. The OsPP2C09 -OE transgenic rice was reported to display hypersensitive phenotypes in response to ABA, drought, and salinity ( Miao et al, 2020 ; Min et al, 2021 ). Interestingly, Figure 7C clearly indicates that the SLR1 protein level was much lower in the OsPP2C09 -OE transgenic rice than in the WT plants in the presence of 5 μM GA 3 or 50 μM ABA.…”

“…OsRF1 could participate in the regulation of ABA signaling and stress responses by controlling the OsPP2C09 protein dynamics under stress conditions. Recently, it was reported that overexpression of OsPP2C09 displayed ABA-insensitive and stress-hypersensitive phenotypes, and that the knock-out mutant of OsPP2C09 showed enhanced stress tolerance and ABA hypersensitivity ( Miao et al, 2020 ; Min et al, 2021 ). Although the OsPP2C09 protein level is known to be regulated by the 26S proteasome pathway ( Miao et al, 2020 ), the mechanism of PP2CA09 degradation is still unknown.…”

“…Recently, it was reported that overexpression of OsPP2C09 displayed ABA-insensitive and stress-hypersensitive phenotypes, and that the knock-out mutant of OsPP2C09 showed enhanced stress tolerance and ABA hypersensitivity ( Miao et al, 2020 ; Min et al, 2021 ). Although the OsPP2C09 protein level is known to be regulated by the 26S proteasome pathway ( Miao et al, 2020 ), the mechanism of PP2CA09 degradation is still unknown. With regard to these reports, we proposed that OsPP2C09 is a target of OsRF1 , and that the regulation of OsPP2C09 protein stability could a mode of action of OsRF1 for conferring drought and salt tolerance.…”

Identification, Evolutionary and Expression Analysis of PYL-PP2C-SnRK2s Gene Families in Soybean

“…Besides, all GmPYLs , GmPP2Cs , and GmSnRK2s genes contain at least one plant hormone response element, and plant hormone signals are the key to regulating drought or water deficiency responses [ 52 ]. Therefore, GmPYL-PP2C-SnRK2s gene families may play an important role in regulating drought or water deficiency responses [ 53 ].…”