Sun Zhuonan, Shen Hui, Chen Zhongtao, Ma Ning, Yang Ye, Liu Hongxia, Li Jie
College of Plant Protection, Shanxi Agricultural University, Taigu, China.
College of Horticulture, Shanxi Agricultural University, Taigu, China.
Front Plant Sci. 2024 May 14;15:1361276. doi: 10.3389/fpls.2024.1361276. eCollection 2024.
Thrips are serious pests of Baroni (daylily), affecting crop yield and quality. To defend against pests, daylily has evolved a set of sophisticated defense mechanisms. In the present study, induction of systemic resistance in 'Datong Huanghua' by feeding was investigated at both biochemical and molecular levels. The soluble sugar content of daylily leaves was significantly lower than that in control check (CK) at all time points of feeding by , whereas the amino acid and free fatty acid contents started to be significantly lower than those in CK after 7 days. Secondary metabolites such as tannins, flavonoids, and total phenols, which are harmful to the growth and reproduction of , were increased significantly. The activities of defense enzymes such as peroxidase (POD), phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO) were significantly increased, and the degree of damage to plants was reduced. The significant increase in protease inhibitor (PI) activity may lead to disrupted digestion and slower growth in . Using RNA sequencing, 1,894 differentially expressed genes (DEGs) were identified between control and treatment groups at five timepoints. DEGs were mainly enriched in secondary metabolite synthesis, jasmonic acid (JA), salicylic acid (SA), and other defense hormone signal transduction pathways, defense enzyme synthesis, MAPK signaling, cell wall thickening, carbohydrate metabolism, photosynthesis, and other insect resistance pathways. Subsequently, 698 DEGs were predicted to be transcription factors, including bHLH and WRKY members related to biotic stress. WGCNA identified 18 hub genes in four key modules (Purple, Midnight blue, Blue, and Red) including MYB-like DNA-binding domain (TRINITY_DN2391_c0_g1, TRINITY_DN3285_c0_g1), zinc-finger of the FCS-type, C2-C2 (TRINITY_DN21050_c0_g2), and NPR1 (TRINITY_DN13045_c0_g1, TRINITY_DN855_c0_g2). The results indicate that biosynthesis of secondary metabolites, phenylalanine metabolism, PIs, and defense hormones pathways are involved in the induced resistance to in daylily.
蓟马是黄花菜的严重害虫，影响作物产量和品质。为抵御害虫，黄花菜进化出了一套复杂的防御机制。在本研究中，从生化和分子水平对取食诱导‘大同黄花’的系统抗性进行了研究。在蓟马取食的所有时间点，黄花菜叶片的可溶性糖含量均显著低于对照（CK），而氨基酸和游离脂肪酸含量在取食7天后开始显著低于CK。对蓟马生长和繁殖有害的次生代谢物如单宁、黄酮类化合物和总酚类物质显著增加。过氧化物酶（POD）、苯丙氨酸解氨酶（PAL）和多酚氧化酶（PPO）等防御酶的活性显著增加，对植物的损害程度降低。蛋白酶抑制剂（PI）活性的显著增加可能导致蓟马消化紊乱和生长减缓。利用RNA测序，在五个时间点的对照组和处理组之间鉴定出1894个差异表达基因（DEG）。DEG主要富集于次生代谢物合成、茉莉酸（JA）、水杨酸（SA）和其他防御激素信号转导途径、防御酶合成、MAPK信号传导、细胞壁加厚、碳水化合物代谢、光合作用和其他抗虫途径。随后，预测有698个DEG为转录因子，包括与生物胁迫相关的bHLH和WRKY成员。加权基因共表达网络分析（WGCNA）在四个关键模块（紫色、深蓝色、蓝色和红色）中鉴定出18个枢纽基因，包括MYB样DNA结合结构域（TRINITY_DN2391_c0_g1、TRINITY_DN3285_c0_g1）、FCS型锌指、C2-C2（TRINITY_DN21050_c0_g2）和NPR1（TRINITY_DN13045_c0_g1、TRINITY_DN855_c0_g2）。结果表明，次生代谢物生物合成、苯丙氨酸代谢、PI和防御激素途径参与了黄花菜对蓟马的诱导抗性。
