Scialò Emanuele, Sicilia Angelo, Continella Alberto, Gentile Alessandra, Lo Piero Angela Roberta
Department of Agriculture, Food and Environment, University of Catania, 951213 Catania, Italy.
Biology (Basel). 2024 Aug 7;13(8):595. doi: 10.3390/biology13080595.
Agriculture faces the dual challenge of increasing food production and safeguarding the environment. Climate change exacerbates this challenge, reducing crop yield and biomass due to drought stress, especially in semi-arid regions where Citrus plants are cultivated. Understanding the molecular mechanisms underlying drought tolerance in Citrus is crucial for developing adaptive strategies. Plants of two citrus rootstocks, Carrizo Citrange and Bitters (C22), were grown in aerated half-strength Hoagland's nutrient solution. Post-acclimation, the plants were exposed to a solution containing 0% (control) or 15% PEG-8000 for 10 days. Leaf malonyl dialdehyde (MDA) and hydrogen peroxide (HO) content were measured to assess the reached oxidative stress level. Total RNA was extracted, sequenced, and de novo-assembled. Weighted Gene Correlation Network Analysis (WGCNA) was conducted to examine the relationship between gene expression patterns and the levels of MDA and HO used as oxidative stress indicators. Plant visual inspection and MDA and HO contents clearly indicate that Bitters is more tolerant than Carrizo towards PEG-induced drought stress. RNA-Seq analysis revealed a significantly higher number of differentially expressed genes (DEGs) in Carrizo (6092) than in Bitters (320), with most being associated with drought sensing, ROS scavenging, osmolyte biosynthesis, and cell wall metabolism. Moreover, the WGCNA identified transcription factors significantly correlated with MDA and HO levels, thus providing insights into drought-coping strategies and offering candidate genes for enhancing citrus drought tolerance.
农业面临着增加粮食产量和保护环境的双重挑战。气候变化加剧了这一挑战，由于干旱胁迫导致作物产量和生物量下降，尤其是在种植柑橘类植物的半干旱地区。了解柑橘耐旱性的分子机制对于制定适应性策略至关重要。将两种柑橘砧木卡里佐枳橙和苦味酸橙（C22）的植株种植在通气的半强度霍格兰营养液中。驯化后，将植株暴露于含有0%（对照）或15%聚乙二醇8000的溶液中10天。测量叶片丙二醛（MDA）和过氧化氢（HO）含量以评估达到的氧化应激水平。提取总RNA、进行测序并进行从头组装。进行加权基因共表达网络分析（WGCNA）以检查基因表达模式与用作氧化应激指标的MDA和HO水平之间的关系。植株外观检查以及MDA和HO含量清楚地表明，苦味酸橙比卡里佐枳橙对聚乙二醇诱导的干旱胁迫更具耐受性。RNA测序分析显示，卡里佐枳橙（6092个）中差异表达基因（DEG）的数量明显高于苦味酸橙（320个），大多数差异表达基因与干旱感知、活性氧清除、渗透溶质生物合成和细胞壁代谢有关。此外，WGCNA鉴定出与MDA和HO水平显著相关的转录因子，从而为干旱应对策略提供了见解，并为增强柑橘耐旱性提供了候选基因。
