Serine hydroxymethyltransferase (SHMT) is one of the most important enzyme families in one-carbon metabolic pathway and photorespiration within plant cells. Recently studies reported the active roles of plant SHMTs in defending abiotic stresses. However, genome-scale analysis of SHMT in tomato is currently unknown. In this study, seven SHMT genes were identified in the tomato genome using a genome-wide search approach. In addition, their physicochemical properties, protein secondary structure, subcellular localization, gene structure, conserved motifs, phylogenetic and collinear relationships were analyzed. Our results demonstrated that tomato SHMT members were divided into two group and four subgroups, and they were conserved with the orthologs of other plants. Analysis of cis-acting elements showed that each of the SlSHMT genes contained different kinds of hormones and stress-related cis-acting elements in their promoter regions. Finally, qRT-PCR analysis indicated that SlSHMTs were expressed at different levels in different tissues, and they responded to UV, cold, heat, NaCl, H2O2, ABA and PEG treatments. These results provided definite evidence that SlSHMTs might involve in growth, development and stress responses in tomato, which laid a foundation for future functional studies of SlSHMTs.

Calmodulin-binding transcription activator (CAMTA) plays an important regulatory role in plant growth, development, and stress response. This study identified the phylogenetic relationships of the CAMTA family in 42 plant species using a genome-wide search approach. Subsequently, the evolutionary relationships, gene structures, and conservative structural domain of CAMTA3/SR1 in different plants were analyzed. Meanwhile, in the promoter region, the cis-acting elements, protein clustering interaction, and tissue-specific expression of CAMTA3/SR1 in tomato were identified. The results show that SlCAMTA3/SR1 genes possess numerous cis-acting elements related to hormones, light response, and stress in the promoter regions. SlCAMTA3 might act together with other Ca2+ signaling components to regulate Ca2+-related biological processes. Then, the expression pattern of SlCAMTA3/SR1 was also investigated by quantitative real-time PCR (qRT-PCR) analysis. The results show that SlCAMTA3/SR1 might respond positively to various abiotic stresses, especially Cd stress. The expression of SlCAMTA3/SR1 was scarcely detected in tomato leaf at the seedling and flowering stages, whereas SlCAMTA3/SR1 was highly expressed in the root at the seedling stage. In addition, SlCAMTA3/SR1 had the highest expression levels in flowers at the reproductive stage. Here, we provide a basic reference for further studies about the functions of CAMTA3/SR1 proteins in plants.

Hydrogen gas (H2) is considered as a signaling molecule and plays multiple roles in plant growth. However, the effect of H2 on postharvest physiology in lily scales during storage has not been reported. In this study, the regulatory roles of hydrogen-rich water (HRW, a H2 donor, a concentration of 0.45 mM for 100% HRW) in water status, ion balance, and nutrients in Lanzhou lily (Lilium davidii var. unicolor) scales were investigated. The scales were soaked in HRW for 12 d, and sampling was performed every 3 d for a total of 5 times. The results show that HRW (0, 10, 50, and 100%) increased the fresh weight, dry weight, relative water content, and water loss rate in lily scales, with maximum biological response at 50% HRW. Treatment with 50% HRW significantly increased the K+ content and K+/Na+ ratio in lily scales and decreased Na+ content. The Na+ K+-ATPase, and PM H+-ATPase activities were also increased by 50% HRW treatment. Meanwhile, 50% HRW up-regulated the expression of AKT1 and HA3 genes and down-regulated the expression of NHX2 and SOS1 genes. In addition, 50% HRW treatment significantly increased the expression level of PIP1;5, PIP2A, TIP1;3, and TIP2;2 genes. Treatment with 50% HRW significantly increased the content of water-soluble carbohydrate, sucrose, glucose, and fructose in lily scales, and decreased the content of starch. In addition, 50% HRW treatment significantly increased the activity of α-amylase, β-amylase, total amylase, sucrose synthase, and sucrose phosphate synthase. Collectively, H2 might enhance the water retention capacity and nutrient content in lily scales by maintaining ion balance, regulating aquaporin, and increasing sugar-metabolizing enzyme activity, thereby prolonging the storage period of postharvest scales of Lanzhou lily.