Zhou Chaowei, Shen Hui, Yan Shangbo, Ma Changyi, Leng Jing, Song Yu, Gao Nan
School of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China.
School of 2011, Nanjing Tech University, Nanjing 211816, China.
Plants (Basel). 2024 Nov 26;13(23):3312. doi: 10.3390/plants13233312.
Acetoin is a volatile organic compound, which is a class of metabolites produced by plant growth-promoting rhizobacteria. The mechanisms underlying plant growth promotion by acetoin and its potential to induce saline stress tolerance in plants are poorly understood. Lettuce ( L. var. ramosa Hort.) seedlings in hydronics and pots under non-saline or saline conditions were foliar-sprayed with 10 mL of 0 or 1 mg·mL acetoin at 7 and 14 d after transplantation and harvested 7 d after the second spray. Shoots and roots of hydroponic lettuce seedlings were harvested at 6 and 24 h after treatment for RNA sequencing. Seedlings sprayed with acetoin showed more vigorous growth, with higher shoot and root biomass than those of the controls, in both hydronic and pot modes. The transcriptomic analysis revealed acetoin application resulted in 177 differentially expressed genes (39 upregulated and 138 downregulated) in shoots and 397 differentially expressed genes (112 upregulated and 285 downregulated) in roots. These DEGs, mainly involved in plant hormone signal transduction and the mitogen-activated protein kinase, have the potential to trigger plants' responses to various environmental stimuli, including stress and developmental signals. Under saline conditions, acetoin-treated plants showed increased net leaf photosynthesis and activities of several defense enzymes, indicating that acetoin enhances both fundamental growth and the plant's stress defenses, especially against salinity. In summary, acetoin appears to act through a complex interplay of genetic and biochemical mechanisms, influencing key signaling pathways and physiological processes that lead to improved growth and stress tolerance in lettuce seedlings.
乙偶姻是一种挥发性有机化合物，属于植物促生根际细菌产生的一类代谢产物。乙偶姻促进植物生长的潜在机制及其诱导植物耐盐胁迫的潜力尚不清楚。在水培和盆栽条件下，将生菜（L. var. ramosa Hort.）幼苗置于非盐或盐胁迫条件下，在移植后第7天和第14天，用10 mL 0或1 mg·mL的乙偶姻进行叶面喷施，并在第二次喷施后7天收获。在处理后6小时和24小时收获水培生菜幼苗的地上部分和根部用于RNA测序。在水培和盆栽模式下，喷施乙偶姻的幼苗均表现出更旺盛的生长，地上部分和根部生物量均高于对照。转录组分析显示，乙偶姻处理导致地上部分有177个差异表达基因（39个上调和138个下调），根部有397个差异表达基因（112个上调和285个下调）。这些差异表达基因主要参与植物激素信号转导和丝裂原活化蛋白激酶，有可能触发植物对各种环境刺激的反应，包括胁迫和发育信号。在盐胁迫条件下，经乙偶姻处理的植物净叶片光合作用增加，几种防御酶的活性增强，这表明乙偶姻既能促进植物基本生长，又能增强植物的胁迫防御能力，尤其是对盐胁迫的防御能力。总之，乙偶姻似乎通过遗传和生化机制的复杂相互作用发挥作用，影响关键信号通路和生理过程，从而提高生菜幼苗的生长和胁迫耐受性。
