Wheat PP2C-a10 regulates seed germination and drought tolerance in transgenic Arabidopsis

Xiaofen Yu,Qian Zhang,Guangyuan He,Guangxiao Yang,Li Li,Jiapeng Han

doi:10.1007/s00299-020-02520-4

Xiaofen Yu, Qian Zhang + Show 4 more

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https://doi.org/10.1007/s00299-020-02520-4

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Abstract

Key messageA wheat protein phosphatase PP2C-a10, which interacted with TaDOG1L1 and TaDOG1L4, promoted seed germination and decreased drought tolerance of transgenic Arabidopsis.Seed dormancy and germination are critical to plant fitness. DELAY OF GERMINATION 1 (DOG1) is a quantitative trait locus for dormancy in Arabidopsis thaliana. Some interactions between DOG1 and the type 2C protein phosphatases (PP2Cs) have been reported in Arabidopsis. However, the research on molecular functions and regulations of DOG1Ls and group A PP2Cs in wheat (Triticum aestivum. L), an important crop plant, is rare. In this study, the whole TaDOG1L family was identified. Expression analysis revealed that TaDOG1L2, TaDOG1L4 and TaDOG1L-N2 specially expressed in wheat grains, while others displayed distinct expression patterns. Yeast two-hybrid analysis of TaDOG1Ls and group A TaPP2Cs revealed interaction patterns differed from those in Arabidopsis, and TaDOG1L1 and TaDOG1L4 interacted with TaPP2C-a10. The qRT-PCR analysis showed that TaPP2C-a10 exhibited the highest transcript level in wheat grains. Further investigation showed that ectopic expression of TaPP2C-a10 in Arabidopsis promoted seed germination and decreased sensitivity to ABA during germination stage. Additionally, TaPP2C-a10 transgenic Arabidopsis exhibited decreased tolerance to drought stress. Finally, the phylogenetic analysis indicated that TaPP2C-a10 gene was conserved in angiosperm during evolutionary process. Overall, our results reveal the role of TaPP2C-a10 in seed germination and abiotic stress response, as well as the functional diversity of TaDOG1L family.

Highlights

Seed dormancy is critical to plants by preventing germination under unfavorable conditions
DELAY OF GERMINATION 1 (DOG1) is critical to the induction of seed dormancy
Six TaDOG1L genes (15 homoeologs) were identified by genome-wide searching (Fig. 1). Another 39 proteins contained the DOG1 domains, but technically belonged to the clade D bZIP transcript factors according to the description of DOG1 family (Bentsink et al 2006)

Summary

Introduction

Seed dormancy is critical to plants by preventing germination under unfavorable conditions. The induction and release of dormancy are mainly controlled by two plant hormones: abscisic acid (ABA) and gibberellins (GA) (Yan and Chen 2017; Vishal and Kumar 2018). ABA participates in the processes of plant growth, development and responses to various abiotic stresses, while GA is involved in various stages of plant growth and development. ABA and GA have antagonistic effects on seed dormancy and germination, i.e., endogenous ABA content is gradually decreased from dormancy to germination phase in the seed, whereas the GA level is increased during this. In Arabidopsis, ABA-deficient mutants accelerate germination (Frey et al 2011), while ABA catabolism mutants display deeper dormancy phenotype (Matakiadis et al 2009)

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