Li Yuwei, Chen Xiaohan, Wang Huantao, Wang Xiaoyu
College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, 266590, Shandong, China.
Plant Cell Rep. 2025 Jul 27;44(8):181. doi: 10.1007/s00299-025-03571-1.
Bioinformatics analysis identified 46 KCS genes in two Medicago species, linking their function to abiotic stresses with MsKCS5 enhancing yeast stress viability. The β-ketoacyl-CoA synthase (KCS) family, encoding pivotal rate-limiting enzymes for very-long-chain fatty acid biosynthesis, plays an indispensable role in plant cuticular wax formation. These hydrophobic layers constitute vital physical barriers that prevent water loss and pathogen penetration while simultaneously participating in stress signal transduction. Through comprehensive genome-wide analysis, 46 KCS genes were identified and characterized from two Medicago species: 19 in Medicago sativa and 27 in Medicago truncatula. Collinearity analysis further delineated the evolutionary trajectory of KCS genes, identifying tandem duplication events as a key driver of family diversification. Conserved motif architecture and exon-intron organization analyses demonstrated significant structural conservation within phylogenetic subgroups, suggesting functional coherence among paralogs. Promoter cis-element profiling uncovered an enrichment of stress-responsive and developmental regulatory motifs, aligning with the dual physiological roles of KCS genes. Transcriptomic analysis combined with RT-qPCR validation revealed differential expression patterns of alfalfa KCS members under drought, salinity, and cold stress, implicating their roles in abiotic stress adaptation. Subcellular localization assays via tobacco transient expression systems confirmed the plasma membrane targeting of MsKCS5, consistent with its putative function in extracellular wax deposition. Functional complementation assays in yeast heterologous expression systems revealed that MsKCS5 rescued stress-sensitive phenotypes, thereby verifying its conserved function in abiotic stress response mechanisms. This multi-omics framework elucidates the evolutionary dynamics and stress-responsive regulatory networks of KCS genes while identifying high-priority candidates for targeted genetic engineering to improve cuticular wax-mediated stress resilience in legume crops.
生物信息学分析在两种苜蓿属植物中鉴定出46个KCS基因，将它们的功能与非生物胁迫联系起来，其中MsKCS5增强了酵母的胁迫生存能力。β-酮脂酰辅酶A合酶（KCS）家族编码超长链脂肪酸生物合成的关键限速酶，在植物表皮蜡质形成中起不可或缺的作用。这些疏水层构成了重要的物理屏障，可防止水分流失和病原体侵入，同时参与胁迫信号转导。通过全面的全基因组分析，从两种苜蓿属植物中鉴定并表征了46个KCS基因：紫花苜蓿中有19个，蒺藜苜蓿中有27个。共线性分析进一步描绘了KCS基因的进化轨迹，确定串联重复事件是家族多样化的关键驱动因素。保守基序结构和外显子-内含子组织分析表明，系统发育亚组内存在显著的结构保守性，这表明旁系同源物之间存在功能一致性。启动子顺式元件分析揭示了胁迫响应和发育调控基序的富集，这与KCS基因的双重生理作用一致。转录组分析结合RT-qPCR验证揭示了苜蓿KCS成员在干旱、盐度和冷胁迫下的差异表达模式，暗示了它们在非生物胁迫适应中的作用。通过烟草瞬时表达系统进行的亚细胞定位分析证实了MsKCS5定位于质膜，这与其在细胞外蜡质沉积中的假定功能一致。酵母异源表达系统中的功能互补分析表明，MsKCS5挽救了胁迫敏感表型，从而验证了其在非生物胁迫响应机制中的保守功能。这个多组学框架阐明了KCS基因的进化动态和胁迫响应调控网络，同时确定了用于靶向基因工程的高优先级候选基因，以提高豆科作物中表皮蜡质介导的胁迫恢复力。
