Characteristics and Expression Analyses of Trehalose-6-Phosphate Synthase Family in Prunus mume Reveal Genes Involved in Trehalose Biosynthesis and Drought Response

Abstract

Trehalose and its key synthase (trehalose-6-phosphate synthase, TPS) can improve the drought tolerance of plants. However, little is known about the roles of trehalose and the TPS family in Prunus mume response to drought. In our study, we discovered that the trehalose content in leaf, root, and stem tissues significantly increased in P. mume in response to drought. Therefore, the characteristics and functions of the TPS family are worth investigating in P. mume. We identified nine TPS family members in P. mume, which were divided into two sub-families and characterized by gene structure, promoter elements, protein conserved domains, and protein motifs. We found that the Hydrolase_3 domain and several motifs were highly conserved in Group II instead of Group I. The distinctions between the two groups may result from selective constraints, which we estimated by the dN/dS (ω) ratio. The ω values of all the PmTPS family gene pairs were evaluated as less than 1, indicating that purity selection facilitated their divergence. A phylogenetic tree was constructed using 92 TPSs from 10 Rosaceae species, which were further divided into five clusters. Based on evolutionary analyses, the five clusters of TPS family proteins mainly underwent varied purity selection. The expression patterns of PmTPSs under drought suggested that the TPS family played an important role in the drought tolerance of P. mume. Combining the expression patterns of PmTPSs and the trehalose content changes in leaf, stem, and root tissues under normal conditions and drought stress, we found that the PmTPS2 and PmTPS6 mainly function in the trehalose biosynthesis in P. mume. Our findings not only provide valuable information about the functions of trehalose and TPSs in the drought response of P. mume, but they also contribute to the future drought breeding of P. mume.

Overexpression of genes encoding enzymes involved in trehalose synthesis from Caragana korshinskii enhances drought tolerance of transgenic plants

“…Nine putative ScTPS genes have been identified in sugarcane hybrids and shown to exhibit divergent expression in response to simulated drought, salinity, and ABA (Hu et al 2020). TPS and TPP genes have also been identified in other plants, including Prunus mume (Yang et al 2020), Moringa oleifera (Lin et al 2018), and Dendrobium officinale (Yu et al 2020), and shown to exhibit various specific expression patterns.…”

Identification of TPS and TPP gene families in Cannabis sativa and their expression under abiotic stresses

“…The formula T = Ks/2r was used to estimate the divergence time of duplicated gene pairs. The r value was 1.5×10 -8 for dicots (Yang et al 2020).…”

“…TPS and TPP enzymes are widely distributed in higher plants. To date, systematic identification and analysis of TPS family genes have been performed in rice (Ge et al 2008), Arabidopsis (Yang et al 2012), Populus (Yang et al 2012), wheat (Xie et al 2015), lotus (Jin et al 2016), cotton (Mu et al 2016), cassava (Han et al 2016), potato , apple (Du et al 2017), drumstick tree (Lin et al 2018), Brachypodium distachyon (Wang et al 2019), sugarcane (Hu et al 2020), Prunus mume (Yang et al 2020), and grapevine (Morabito et al 2021). Some genes show potential functions under stress conditions, but their expression patterns are also diverse.…”

Hormonal Crosstalk and Root Suberization for Drought Stress Tolerance in Plants

“…Drought tends to accumulate the level of soluble sugars in the roots ( Figure 2 ) of Arabidopsis [ 65 , 66 ], maize [ 67 ], and rice [ 68 ]. In particular, monosaccharides including glucose, fructose, and trehalose are abundant in rice [ 69 ], Medicago [ 47 ], and Prunus [ 70 ] as a consequence of drought.…”

“…T6P, an essential moderator for sugar metabolism in plants [ 71 ], is an indicator of ABA signaling-responsive snf1-related kinase (SnRK1) activity and play a key role in modulating cellular sucrose homeostasis via negative feedback to sucrose [ 72 ]. Indeed, the level of trehalose was preferentially enhanced by drought stress in several crop plants including rice and soybean, and these responses were commonly observed in wild type and mutant (drought-resistant) lines [ 69 , 70 , 73 , 78 , 79 , 80 , 81 , 82 ]. Under stress conditions, SnRK1, a sensory protein that regulates gene expression in relation to cellular energy levels, not only regulates plant development and signal perception, down-stream reactions, and cellular homeostasis [ 83 ] but also acts in an opposing way against target of rapamycin (TOR), a crucial protein in plant growth and development [ 84 ].…”