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Graphical abstract Highlights • Combining dynamic changing SOD, MDA, soluble sugar and proline contents and the degree of leaf damage under stress, samples of 8 h and 24 h after heat, drought and combined stress treatments were selected for RNA-seq. • The RNA sequencing analysis demonstrated that many genes involved in the defense response, photosynthesis, metabolic process, etc. are differentially expressed in response to drought and heat. However, 1468 and 1220 upregulated and 1146 and 686 downregulated genes were confirmed as overlapping differentially expressed genes at 8 h and 24 h after treatment, and these genes are mainly involved in transport, binding and defense responses. • Comparison of single and combined stress suggests the combined stress did not result in a simple additive response, and that there may be a synergistic response to the combination of drought and heat in soybean. • TFs in the single and combination stress were identified from DEGs, which classified into 9 clusters according to expression levels of six treatment and one control groups, revealed dynamic changing TF expression profiles and molecular mechanisms in response to single and combination stress. Abstract Heat and drought are the two major abiotic stress limiting soybean growth and output worldwide. Knowledge of the molecular mechanisms underlying the responses to heat, drought, and combined stress is essential for soybean molecular breeding. In this study, RNA-sequencing was used to determine the transcriptional responses of soybean to heat, drought and combined stress. RNA-sequencing analysis demonstrated that many genes involved in the defense response, photosynthesis, metabolic process, etc. are differentially expressed in response to drought and heat. However, 1468 and 1220 up-regulated and 1146 and 686 down-regulated genes were confirmed as overlapping differentially expressed genes at 8 h and 24 h after treatment, and these genes are mainly involved in transport, binding and defense response. Furthermore, we compared the heat, drought and the combined stress-responsive genes and identified potential new targets for enhancing stress tolerance of soybean. Comparison of single and combined stress suggests the combined stress did not result in a simple additive response, and that there may be a synergistic response to the combination of drought and heat in soybean. [ABSTRACT FROM AUTHOR]

Amino acid transporters (AATs) are integral membrane proteins responsible for the transmembrane transport of amino acids and play important roles in various physiological processes of plants. However, there has not yet been a genome-wide overview of the StAAT gene family to date and only StAAP1 has been previously studied in potato. In this paper, a total of 72 StAATs were identified using a series of bioinformatics searches and classified into 12 subfamilies based on their phylogenetic relationship with known Arabidopsis and rice AATs. Chromosomal localization revealed their distribution on all 12 chromosomes. Nearly one-third of StAAT genes (23 of 72) were derived from gene duplication, among which tandem duplication made the greatest contribution to the expansion of the StAAT family. Motif analysis showed that the same subfamily had similar conserved motifs in both numbers and varieties. Moreover, high-throughput sequencing data was used to analyze the expression patterns of StAAT genes and was verified by quantitative real-time RT-PCR. The expression of StAAT genes exhibited both abundant and tissue-specific expression patterns, which might be connected to their functional roles in long- and short-distance transport. This study provided a comprehensive survey of the StAAT gene family, and could serve as a theoretical foundation for the further functional identification and utilization of family members. [ABSTRACT FROM AUTHOR]

The Auxin/indole-3-acetic acid ( Aux/IAA ) genes encode short-lived nuclear proteins that are known to be involved in the primary cellular responses to auxin. To date, systematic analysis of the Aux/IAA genes in potato ( Solanum tuberosum ) has not been conducted. In this study, a total of 26 potato Aux/IAA genes were identified (designated from StIAA1 to StIAA26 ), and the distribution of four conserved domains shared by the StIAAs were analyzed based on multiple sequence alignment and a motif-based sequence analysis. A phylogenetic analysis of the Aux/IAA gene families of potato and Arabidopsis was also conducted. In order to assess the roles of StIAA genes in tuber development, the results of RNA-seq studies were reformatted to analyze the expression patterns of StIAA genes, and then verified by quantitative real-time PCR. A large number of StIAA genes (12 genes) were highly expressed in stolon organs and in during the tuber initiation and expansion developmental stages, and most of these genes were responsive to indoleacetic acid treatment. Our results suggested that StIAA genes were involved in the process of tuber development and provided insights into functional roles of potato Aux/IAA genes. [ABSTRACT FROM AUTHOR]