OsTPP1 regulates seed germination through the crosstalk with abscisic acid in rice

Abstract

Seed germination is essential for direct seeding in rice. It has been demonstrated that trehalose-6-phosphate phosphatase 1 (OsTPP1) plays roles in improving yield and stress tolerance in rice.In this study, the roles of OsTPP1 on seed germination in rice were investigated. The tpp1 mutant germinated slower than the wild-type (WT), which can be restored by exogenous trehalose. tpp1 seeds showed higher ABA content compared with WT seeds. The tpp1 mutant was hypersensitive to ABA and ABA catabolism inhibitor (Dinicozanole). Furthermore, two ABA catabolism genes were downregulated in the tpp1 mutant which were responsible for increased ABA concentrations, and exogenous trehalose increased transcripts of ABA catabolism genes, suggesting that OsTPP1 and ABA catabolism genes acted in the same signaling pathway.Further analysis showed that a transcription factor of OsGAMYB was an activator of OsTPP1, and expression of OsGAMYB was decreased by both the exogenous and endogenous ABA, subsequently reducing the expression of OsTPP1, which suggested a new signaling pathway required for seed germination in rice. In addition, ABA-responsive genes, especially OsABI5, were invoved in OsTPP1-mediated seed germination.Overall, our study provided new pathways in seed germination that OsTPP1 controlled seed germination through crosstalk with the ABA catabolism pathway.

Analysis of gene expression in early seed germination of rice: landscape and genetic regulation

“…After that, we collected the germinating seeds at 6 h and 24 h after imbibed in the pure water. RNA sequencing (RNA-seq) libraries generated from total RNA with three independent replicates at 6 h and 24 h time points were deployed for the following analysis [ 20 ].

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“…Imbibed seeds at 6 h, 12 h and 24 h after imbibition were harvested for enzyme extraction as previously described [ 20 ]. The assay kit from Jiancheng, biotechcompany (Nanjing, China) was used in this study.…”

In Silico and Transcription Analysis of Trehalose-6-phosphate Phosphatase Gene Family of Wheat: Trehalose Synthesis Genes Contribute to Salinity, Drought Stress and Leaf Senescence

“…The TPP gene family has been characterized as catalytic enzymes that mainly function in trehalose biosynthesis [18,76,77]. Despite their catalytic function, a portion of TPP genes has been identified to be involved in growth and development, response in abiotic and biotic stress and senescence [27][28][29][31][32][33]35,42,78,79]. Although wheat is one of the most economically important cereal crops, systemic studies on TPP homologs in wheat have not been reported yet.…”

“…al. [27] reported that seed germination was regulated by OsTPP1 via crosstalk with the ABA catabolism pathway. In addition, high expression was also observed for TaTPP1, TaTPP8 and TaTPP9 in all developmental stages except dough development and ripening, suggesting that these genes might have a significant association with wheat developmental processes.…”

“…T6P is a signaling metabolite in plants that links growth and development to carbon metabolism and serves as a signal of sucrose status at various phases of the plant's development [20][21][22]. TPS genes were discovered to be involved in the germination of seeds, stress signaling, vegetative phase separation, shoot branching, and flowering time regulation in Arabidopsis and rice, with TPS1 being the most studied [23][24][25][26][27]. Instead, TPP was found to inhibit SnRK1 (Sn1-related protein kinase) activity, a well-known transcriptional regulatory pathway under stress and energy metabolism [28].…”