Abiotic stimuli severely restrict the growth and development of plants, resulting in massive losses in the quality and yield of crops. Exploring genes that can improve crop tolerance to abiotic stress is important. In a previous study, we found that overexpression of the Arabidopsis nucleotide-binding domain leucine-rich repeat (NB-LRR) gene AtRPM1(D505V) increased disease resistance in rice. In this research, we found that AtRPM1(D505V) transgenic plants were more sensitive to abscisic acid (ABA) than wild type (WT) plants. Abiotic-stress resistance in AtRPM1(D505V) transgenic plants was investigated. We found that AtRPM1(D505V) transgenic plants exhibited improved resistance to drought and salt stress; the phonotype and survival rates of transgenic rice were better than WT plants. The expression of stress responsive genes including OsDREB2A, OsDREB2B, OsRD22, and OsRD29A were significantly upregulated in AtRPM1(D505V) overexpressed plants than in WT plants. Moreover, the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were significantly increased in AtRPM1(D505V) overexpressed plants than in WT plants under drought and salt stress. Under cold stress, the expression of stress responsive genes and the activities of antioxidant enzymes in AtRPM1(D505V) transgenic plants were significantly lower than in WT plants. Our research demonstrated that AtRPM1(D505V) confers drought and salt resistance to transgenic rice. Therefore, AtRPM1(D505V) could act as a potential candidate gene to cultivate drought- and salt-tolerant plants.

Amino acid transporters (AATs) allow the transport of amino acids and play important roles in the various physiological processes and environmental responses of plants. The lysine and histidine transporter (LHT) subfamily is an important type of AAT. However, a genome-wide overview of the LHT gene family has not been conducted in L. macranthoides Hand.-mazz. In this study, 11 LHT genes were identified in the Lonicera macranthoides genome. To further understand the functions of LmLHT genes, the gene and protein characteristics, transmembrane helices, evolutionary relationships, chromosomal distribution, cis-acting elements of promoters, and expression patterns were systematically analyzed. According to the results, LmLHT genes were divided into two groups based on the phylogenetic analysis. Transmembrane helices of LmLHT proteins ranged from seven to 16. Gene structure and conserved motif analysis revealed that exon-intron structures and motifs were relatively conserved in the LmLHT family. LmLHT genes were distributed on six of the nine chromosomes and had the most collinear gene pairs with NtLHT genes. Additionally, phytohormones, low-temperature, drought-inducibility, defense and stress related cis-acting elements were enriched in the promoters of LmLHT genes. LmLHT genes showed distinct or preferential expression patterns in various tissues, signifying their potential roles in plant growth and development. We also found that some LmLHT genes were responsive to cold and drought stresses, indicating their roles in abiotic stress adaptation. Overall, our results provided comprehensive insight into the LmLHT gene family and will be useful for future functional analyses.

The exocyst is a hetero-octameric complex that exhibits significant functional diversity in regulating biological processes and defense responses. In plants, the EXO70 proteins are important components of the exocyst complex and are involved in membrane trafficking, biotic and abiotic interactions, as well as cell wall formation. A previous study has indicated that a member of the EXO subfamily, EXO70E2, interacts with RIN4 to mediate plant immunity. In this study, we found that EXO70E2 interacts with the RING-type E3 ligase Botrytis susceptible1 interactor (BOI), and the C-terminal domain of BOI is necessary for its interaction with EXO70E2. Moreover, the protein level of EXO70E2 was degraded and ubiquitinated by BOI in vitro. Collectively, our study reveals a mechanism for regulating the stability of EXO70E2 by a RING-type E3 ligase BOI-mediated ubiquitination.

Nucleotide-binding and leucine-rich repeat receptors (NLRs) play an important role in plant innate immunity. Previous reports indicate that SUT1 (SUPPRESSOR OF TOPP4 1) is required for the autoimmune response mediated by TYPE ONE PROTEIN PHOSPHATASE 4 (TOPP4) mutation topp4-1 (namely TOPP4^T246M) in Arabidopsis. We observed that co-expression of SUT1 with TOPP4 mutant versions, instead of wild-type TOPP4, produced robust cell death in N. benthamiana. The YFP-labeled SUT1 was localized on the plasma membrane (PM), and Gly2, Cys4, and Ser6 are crucial amino acid sites for its PM localization and function. Further dissection proclaimed that the function and localization of SUT1 are influenced by mutations in conserved specific residues. These findings may provide a new perspective for elucidating the activation mechanism of SUT1.