Transcriptomic and physiological analysis reveals interplay between salicylic acid and drought stress in citrus tree floral initiation
Transcriptomic and physiological analysis reveals interplay between salicylic acid and drought stress in citrus tree floral initiation
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转录组和生理分析揭示了水杨酸与柑橘树花萌发过程中干旱胁迫之间的相互作用
DOI：
10.1007/s00425-021-03801-2
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发表时间：
2022-01-01
期刊：
影响因子：
4.3
通讯作者：
Zhang, Jin-Zhi
中科院分区：
文献类型：
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作者：
Khan, Faiza Shafique;Gan, Zhi-Meng;Zhang, Jin-Zhi
主要结论水杨酸（SA）和干旱胁迫促进了甜橙色的更多开花。通过转录组分析发现了应力诱导的花卉开始的生理反应和分子机制。鉴定了许多开花调节的基因，并在异位表达的CSLIP2A促进了拟南芥的早期开花。花开始是与外部因素相关的关键发育机制，柑橘开花主要受干旱压力调节。然而，关于与柑橘中压力诱导的开花有关的复杂的调节网络知之甚少。为了了解柑橘花的分子机制，在水杨酸（SA）和干旱（DR）的联合处理下，对柑橘Sinensis树的花朵诱导进行了花诱导。生理分析表明，SA治疗通过增加抗氧化剂酶活性（SOD，POD和CAT），相对叶水含量，总叶绿素和脯氨酸含量并促进比干旱治疗更多的开花，从而显着使干旱胁迫的剧烈效果归一化。对不同处理的叶子中转录组变化的分析表明，与井相比，与DR，SD（SA + DR）和SA（SA + Well Water）相比，揭示了1135、2728和957差异表达的基因（DEG）。分别浇水。与水回收率相比，总共在DR，SD和SA中表达了总共2415、2318和1933摄氏度。与DR处理的植物相比，在SA处理的干旱植物中，一些关键的开花基因在经过SA处理的干旱植物中更高。 GO富集表明，SA治疗在干旱条件下增强了分生组织活动的调节和生长，但没有发现这种途径在对照中高度富集。此外，我们专注于各种激素，糖，淀粉代谢和与生物合成相关的基因。 KEGG分析表明，富含淀粉蔗糖代谢和荷尔蒙信号转导途径的DEG可能解释了应激诱发的柑橘花的开始。此外，SD处理将柑橘lipoyltransfersae 2a同源（LIP2A）基因上调。 Cslip2a的异位表达在转基因拟南芥中表现出早期开花。综上所述，这项研究提供了新的见解，该见解有助于柑橘树的花卉开始，并为木本树中压力引起的花卉启动提供了极好的参考。
Main conclusionSalicylic acid (SA) and drought stress promote more flowering in sweet orange. The physiological response and molecular mechanism underlying stress-induced floral initiation were discovered by transcriptome profiling. Numerous flowering-regulated genes were identified, and ectopically expressedCsLIP2Apromotes early flowering inArabidopsis.AbstractFloral initiation is a critical developmental mechanism associated with external factors, and citrus flowering is mainly regulated by drought stress. However, little is known about the intricate regulatory network involved in stress-induced flowering in citrus. To understand the molecular mechanism of floral initiation in citrus, flower induction was performed on pottedCitrus sinensistrees under the combined treatment of salicylic acid (SA) and drought (DR).Physiological analysis revealed that SA treatment significantly normalized the drastic effect of drought stress by increasing antioxidant enzyme activities (SOD, POD, and CAT), relative leaf water content, total chlorophyll, and proline contents and promoting more flowering than drought treatment. Analysis of transcriptome changes in leaves from different treatments showed that 1135, 2728 and 957 differentially expressed genes (DEGs) were revealed in response to DR, SD (SA + DR), and SA (SA + well water) treatments in comparison with the well watered plants, respectively. A total of 2415, 2318 and 1933 DEGs were expressed in DR, SD, and SA in comparison with water recovery, respectively. Some key flowering genes were more highly expressed in SA-treated drought plants than in DR-treated plants. GO enrichment revealed that SA treatment enhances the regulation and growth of meristem activity under drought conditions, but no such a pathway was found to be highly enriched in the control. Furthermore, we focused on various hormones, sugars, starch metabolism, and biosynthesis-related genes. The KEGG analysis demonstrated that DEGs enriched in starch sucrose metabolism and hormonal signal transduction pathways probably account for stress-induced floral initiation in citrus. In addition, a citrusLIPOYLTRANSFERSAE 2Ahomologous (LIP2A) gene was upregulated by SD treatment. Ectopic expression ofCsLIP2Aexhibited early flowering in transgenicArabidopsis. Taken together, this study provides new insight that contributes to citrus tree floral initiation under the SA-drought scenario as well as an excellent reference for stress-induced floral initiation in woody trees.