Integrated analysis of transcriptome, metabolome, and histochemistry reveals the response mechanisms of different ages Panax notoginseng to root-knot nematode infection

• Published in: Frontiers in plant science Vol. 14; p. 1258316
• Main Authors: Wang, Zhuhua, Wang, Wenpeng, Wu, Wentao, Wang, Huiling, Zhang, Shuai, Ye, Chen, Guo, Liwei, Wei, Zhaoxia, Huang, Hongping, Liu, Yixiang, Zhu, Shusheng, Zhu, Youyong, Wang, Yang, He, Xiahong
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 14-09-2023
• Subjects: lignin; metabolome; Panax notoginseng; phenylpropanoid pathways; Plant Science; root-knot nematode; transcriptome
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2023.1258316

Panax notoginseng
(
P. notoginseng
) is an invaluable perennial medicinal herb. However, the roots of
P. notoginseng
are frequently subjected to severe damage caused by root-knot nematode (RKN) infestation. Although we have observed that
P. notoginseng
possessed adult-plant resistance (APR) against RKN disease, the defense response mechanisms against RKN disease in different age groups of
P. notoginseng
remain unexplored. We aimed to elucidate the response mechanisms of
P. notoginseng
at different stages of development to RKN infection by employing transcriptome, metabolome, and histochemistry analyses. Our findings indicated that distinct age groups of
P. notoginseng
may activate the phenylpropanoid and flavonoid biosynthesis pathways in varying ways, leading to the synthesis of phenolics, flavonoids, lignin, and anthocyanin pigments as both the response and defense mechanism against RKN attacks. Specifically, one-year-old
P. notoginseng
exhibited resistance to RKN through the upregulation of 5-O-p-coumaroylquinic acid and key genes involved in monolignol biosynthesis, such as PAL, CCR, CYP73A, CYP98A, POD, and CAD. Moreover, two-year-old
P. notoginseng
enhanced the resistance by depleting chlorogenic acid and downregulating most genes associated with monolignol biosynthesis, while concurrently increasing cyanidin and ANR in flavonoid biosynthesis. Three-year-old
P. notoginseng
reinforced its resistance by significantly increasing five phenolic acids related to monolignol biosynthesis, namely p-coumaric acid, chlorogenic acid, 1-O-sinapoyl-D-glucose, coniferyl alcohol, and ferulic acid. Notably,
P. notoginseng
can establish a lignin barrier that restricted RKN to the infection site. In summary,
P. notoginseng
exhibited a potential ability to impede the further propagation of RKN through the accumulation or depletion of the compounds relevant to resistance within the phenylpropanoid and flavonoid pathways, as well as the induction of lignification in tissue cells.