Like other abiotic stresses, salt stress has become a major factor that restricts the growth, distribution and yield of crops. Research has shown that increasing the nitrogen content in soil can improve the salt tolerance of plants and nitrate transporter (NRT) is the primary nitrogen transporter in plants. Suaeda salsa (L.) Pall is a strong halophyte that can grow normally at a salt concentration of 200 mM. The salt stress transcriptome database of S. salsa was found to contain four putative genes that were homologous to NRT, including SsNRT1.1A, SsNRT1.1B, SsNRT1.1C and SsNRT1.1D. The cDNA of SsNRT1.1s was predicted to contain open reading frames of 1791, 1782, 1755 and 1746 bp, respectively. Sequence alignment and structural analysis showed that the SsNRT1.1 amino acids were inducible by salt and have conserved MFS and PTR2 domains. Subcellular localization showed they are on the endoplasmic reticulum. Overexpression of SsNRT1.1 genes in transgenic Arabidopsis improves its salt tolerance and SsNRT1.1C was more effective than others. We constructed a salt-stressed yeast cDNA library and used yeast two-hybrid and BiFC technology to find out that SsHINT1 and SsNRT1.1C have a protein interaction relationship. Overexpression of SsHINT1 in transgenic Arabidopsis also improves salt tolerance and the expressions of Na⁺ and K⁺ were increased and reduced, respectively. But the K⁺/Liratio was up-regulated 11.1-fold compared with the wild type. Thus, these results provide evidence that SsNRT1.1C through protein interactions with SsHINT1 increases the K⁺/Na⁺ ratio to improve salt tolerance and this signaling may be controlled by the salt overly sensitive (SOS) pathway.

The nitrate signaling core regulator NLP7 is known to negatively regulate salt tolerance in Arabidopsis thaliana, but the function of the (SsNLP7A) gene in the halophyte Suaeda salsa remains unclear. To investigate whether SsNLP7A participates in salt stress responses, this study heterologously overexpressed the gene in tomato (Solanum lycopersicum) and systematically evaluated its function under salt stress through phenotypic, physiological, and transcriptomic analyses. The results indicate that SsNLP7A overexpression significantly promotes tomato root development and alleviates growth inhibition caused by salt stress. Under salt treatment, transgenic plants exhibited significantly higher chlorophyll content, accumulation of osmotic regulators (proline and soluble sugars), and antioxidant enzyme (POD, CAT, SOD) activity compared to wild-type plants. Transcriptome analysis further revealed that SsNLP7A enhances salt tolerance by regulating carbon metabolism, phytohormone signaling pathway, photosynthesis, and antioxidant pathways. Collectively, this study elucidates the positive regulatory role of SsNLP7A in salt stress response, providing new insights into its molecular mechanisms.

The Ankyrin-repeat proteins (ANKs) play a key role in plant development and in response to abiotic stress. This research identified family members of the ANK genes in Sorghum bicolor at the whole-genome level, analyzed their sequence characteristics, evolutionary relationships, and expression patterns, and provided a scientific basis for elucidating the functionality of SbANK genes and for salt-tolerant breeding. Using bioinformatics methods, this study conducted a comprehensive identification of the SbANK gene family, analyzing its physicochemical properties, domain composition, chromosomal distribution, colinearity relationships, promoter cis-acting elements, and conserved protein motifs. Transcriptomic data and qRT-PCR were used to detect changes in their expression under salt stress. A total of 186 ANK family members were identified in the Sorghum bicolor genome, classified into 13 subfamilies and unevenly distributed across 10 chromosomes. Intra-species colinearity analysis revealed 7 pairs of duplicated genes, while inter-species colinearity analysis showed that S. bicolor and Oryza sativa share 88 pairs of orthologs, far exceeding the number found in Arabidopsis thaliana (11 pairs). Promoter analysis indicated that SbANK genes are enriched with cis-acting elements associated with hormone responses (particularly MeJA elements, accounting for 51.7%) and stress responses (particularly anaerobic-inducible elements, accounting for 60.9%). Transcriptomic expression analysis revealed that SbANK genes exhibit distinct tissue specificity, with the ANK-IQ subfamily highly expressed in leaves and the ANK-M subfamily showing the most widespread response under salt stress. Expression levels of the 10 candidate genes showing the most significant responses to salt stress were analyzed using qRT-PCR. The results indicated that SbANK91, SbANK135, and SbANK136 were significantly upregulated under 200 mmol/L NaCl treatment. The SbANK family is distinguished by a large number of member genes and structural diversity, with the ANK-M subfamily being the primary group responding to salt stress. SbANK91, SbANK135, and SbANK136 are identified as putative candidate genes for salt stress responses.

Background: Sucrose metabolism plays a crucial role in plant responses to abiotic stresses such as drought and high temperatures, significantly influencing plant growth and yield formation. In higher plants, the second step in sucrose bioconversion involves sucrose phosphate phosphatase (SPP) hydrolyzing sucrose-6-phosphate to form sucrose. This study determined the number of SPP gene family members in upland cotton (Gossypium hirsutum), systematically analyzed their fundamental characteristics, physicochemical properties, phylogenetic relationships, chromosomal localization, and expression patterns across different tissues and under various abiotic stresses. Methods: The SPP gene family in hirsutum was identified using Hidden Markov Models (HMMER) and the NCBI Conserved Domain Database (NCBI CDD), and its physico-chemical properties were analyzed via the SOPMA online analysis website. Phylogenetic relationships were determined using MEGA 12.0 software. Promoter regions were analyzed with PlantCARE, sequence patterns were identified via MEME, and transcriptome data were downloaded from the CottonMD database. Results: This study identified four members of the hirsutum SPP gene family, with amino acid lengths ranging from 335 to 1015, molecular weights between 38.38 and 113.28 kDa, and theoretical isoelectric points (pI) between 5.39 and 6.33. These genes are localized across four chromosomes. The SPP gene family in hirsutum exhibits closer phylo-genetic relationships with SPP genes in Arabidopsis thaliana and Chenopodium quinoa. Their promoter regions are rich in cis-elements associated with multiple abiotic stress resistance functions, and their expression patterns vary across different tissues and under different abiotic stress conditions. Conclusions: The GhSPP gene may play an important role in the growth and development of upland cotton and its responses to salt stress and drought. Therefore, it could be considered as a candidate gene for future functional analysis of cotton resistance to salt and drought stress.

SMXL proteins serve as central regulators of strigolactone (SL) and karrikin (KAR) signaling pathways, orchestrating key developmental processes including shoot branching, floral transition, photomorphogenesis and stress responses. However, the SMXL gene family has not been systematically characterized in Lavandula angustifolia. We identified 37 LaSMXL genes in the lavender genome. Phylogenetic and synteny analyses classified these proteins into four subgroups (Groups I–IV) and indicated that family expansion in lavender was mainly driven by whole-genome and segmental duplications, with most duplicated pairs evolving under strong purifying selection. Gene structure and motif analyses revealed high conservation within each subgroup. Promoter cis-element analysis suggested that LaSMXL genes are integrated into light-, hormone- and stress-responsive regulatory networks. RNA-seq profiling showed that most LaSMXL genes are weakly expressed, but a small subset displays pronounced tissue specificity and clear transcriptional responses to low temperature. Protein–protein interaction predictions and co-expression network analysis further placed highly expressed LaSMXLs within conserved SL/KAR and chloroplast/light-associated modules, alongside D14, KAI2, MAX2, CCD7/CCD8, and CYP711A. Together, these findings provide the first comprehensive overview of the SMXL gene family in lavender and identify candidate LaSMXL genes for future functional studies aimed at optimizing plant architecture and inflorescence-derived essential oil biosynthesis.

Sweet sorghum, a high-quality forage and energy crop, is significantly affected by drought, the primary abiotic stress impacting its growth. Melatonin (MT) has emerged as a crucial signaling molecule in plant responses to abiotic stress. This study investigates the role of melatonin in enhancing drought tolerance in sweet sorghum, specifically using the ‘Dali Shi’ variety under polyethylene glycol (PEG)-induced drought conditions. Our findings demonstrate that exogenous melatonin application significantly increased proline content (by 27.76% and 5.95% under mild and moderate drought, respectively) while decreasing malondialdehyde (MDA) levels (by 18.33% and 35.18%, respectively). Melatonin also enhanced the accumulation of photosynthetic pigments, including chlorophyll b and total chlorophyll, and improved photosynthetic fluorescence parameters (Fv/Fm and ETR). Additionally, melatonin treatment improved root vitality, stimulated carbon and nitrogen metabolism, and increased antioxidant enzyme activity. Transcriptomic analysis revealed that differentially expressed genes were enriched in pathways related to carbon fixation, glycolysis/gluconeogenesis, nitrogen metabolism, antioxidant defense, and plant hormone signaling. Notably, melatonin upregulated key genes associated with these pathways and activated bHLH and MYB transcription factors. In conclusion, this study elucidates the mechanisms by which melatonin enhances sweet sorghum’s drought tolerance, highlighting its potential as a practical approach for improving drought resistance in this crop.