Xiaojia Yin

Background: Sulfate transporters (SULTRs) are integral membrane proteins responsible for sulfate uptake, translocation, and plant adaptation to abiotic stresses. However, knowledge regarding the SULTR gene family in the economically important crop, Brassica rapa (Chinese cabbage), limited. The aim of this study is to conduct a genome-wide identification and functional characterization of BrSULTR genes and to explore their potential functions under abiotic stress. Methods: We identified 19 BrSULTR genes in the B. rapa genome by performing homology searches with Arabidopsis thaliana SULTR sequences as queries. Subsequent bioinformatics analysis included phylogenetic classification, chromosomal localization, gene structure, conserved motif dissection, cis-regulatory element prediction, and protein–protein interaction (PPI) network analysis. Tissue-specific expression profiles of BrSULTRs were assessed using publicly available transcriptome data. Furthermore, their expression dynamics under salt (150 mM NaCl) and low-temperature (4 °C) stress were investigated by integrating transcriptomic, proteomic, and qRT-PCR data. Results: The 19 identified BrSULTR members were phylogenetically categorized into four subfamilies and were mapped unevenly across seven chromosomes. Promoter analysis identified an array of cis-regulatory elements associated with development, hormone response, and stress response. Expression profiles revealed distinct tissue-specific patterns in roots, stems, leaves, flowers, and siliques. Under salt stress, BrSULTR13 was significantly upregulated, while BrSULTR9 and BrSULTR11 were significantly suppressed under low-temperature stress. PPI network projection indicated that the Arabidopsis homologs of BrSULTR5 may physically interact with stress-regulating enzymes such as APS and APR. Conclusions: Our work presents a comprehensive genomic and functional overview of the BrSULTR gene family in B. rapa. The results underscore the potential functions of BrSULTRs, highlighting their involvement in sulfate transport and abiotic stress responses. These insights establish valuable insights and a foundation for further research aiming at improving stress tolerance in B. rapa through the manipulation of sulfur metabolism pathways.

Soil salinization and alkalization are important abiotic stresses that affect crop growth and yield. Development of salt and alkali tolerant varieties is still dominated by the following conventional breeding method: The salt and alkali tolerant traits from screened germplasm are introduced into elite varieties by means of hybridization and backcrossing. In recent years, the breeding of salt and alkali tolerant rice has also made great progress. For example, the yield of Chao‐You 1000, a two‐line rice hybrid, has reached 12.04 t/ha growing in fields with salinity between 0.2% and 0.6%. This review is an update on the progress of salt and alkali tolerant rice germplasm screening and new salt and alkali tolerant varieties in development. By reviewing the performance of current rice hybrids in China's National Regional Variety Trials of Saline‐Alkali Tolerant Rice, we proposed the technical approach of developing saline–alkali tolerant rice hybrids using the third‐generation hybrid rice technology and furthermore the trend of developing salt and alkali tolerant rice hybrids.