College of Horticulture, Shenyang Agricultural University, 120 Dongling Road Shenhe District, Shenyang 110866, China.
Int J Mol Sci. 2023 Mar 25;24(7):6202. doi: 10.3390/ijms24076202.
Cucumber ( L.), sensitive to cold stress, is one of the most economically important vegetables. Here, we systematically investigated the roles of exogenous glycine betaine, chitosan, and chitosan oligosaccharide in alleviating cold stress in cucumber seedlings. The results showed that 50 mg·L chitosan oligosaccharide had the best activity. It effectively increases plant growth, chlorophyll content, photosynthetic capacity, osmotic regulatory substance content, and antioxidant enzyme activities while reducing relative electrical conductivity and malondialdehyde levels in cucumber seedlings under cold stress. To reveal the protective effects of chitosan oligosaccharide in cold stress, cucumber seedlings pretreated with 50 mg·L chitosan oligosaccharide were sampled after 0, 3, 12, and 24 h of cold stress for transcriptome analysis, with distilled water as a control. The numbers of differentially expressed genes in the four comparison groups were 656, 1274, 1122, and 957, respectively. GO functional annotation suggested that these genes were mainly involved in "voltage-gated calcium channel activity", "carbohydrate metabolic process", "jasmonic acid biosynthetic", and "auxin response" biological processes. KEGG enrichment analysis indicated that these genes performed important functions in "phenylpropanoid biosynthesis", "MAPK signaling pathway-plant", "phenylalanine metabolism", and "plant hormone signal transduction." These findings provide a theoretical basis for the use of COS to alleviate the damage caused by cold stress in plant growth and development.
黄瓜（L.）对冷胁迫敏感，是最重要的经济作物之一。在这里，我们系统地研究了外源甘氨酸甜菜碱、壳聚糖和壳寡糖在缓解黄瓜幼苗冷胁迫中的作用。结果表明，50mg·L 的壳寡糖活性最佳。它有效地增加了植物的生长、叶绿素含量、光合作用能力、渗透调节物质含量和抗氧化酶活性，同时降低了冷胁迫下黄瓜幼苗的相对电导率和丙二醛水平。为了揭示壳寡糖在冷胁迫下的保护作用，用 50mg·L 壳寡糖预处理黄瓜幼苗，在冷胁迫 0、3、12 和 24 小时后取样进行转录组分析，以蒸馏水为对照。四个比较组的差异表达基因数量分别为 656、1274、1122 和 957。GO 功能注释表明，这些基因主要参与“电压门控钙通道活性”、“碳水化合物代谢过程”、“茉莉酸生物合成”和“生长素反应”等生物学过程。KEGG 富集分析表明，这些基因在“苯丙烷生物合成”、“植物 MAPK 信号通路”、“苯丙氨酸代谢”和“植物激素信号转导”中发挥重要作用。这些发现为利用 COS 缓解冷胁迫对植物生长发育的损害提供了理论依据。
