Comparative analyses reveal a phenylalanine ammonia lyase dependent and salicylic acid mediated host resistance in Zingiber zerumbet against the necrotrophic soft rot pathogen Pythium myriotylum

被引：4

作者：

Augustine, Lesly ^{[1
,2
,3
]}

Varghese, Lini ^{[1
,2
]}

Kappachery, Sajeesh ^{[1
,2
,4
]}

Ramaswami, Vinitha Meenakshy ^{[1
]}

Surendrababu, Swathy Puthanvila ^{[1
,2
,5
]}

Sakuntala, Manjula ^{[1
]}

Thomas, George ^{[1
]}

机构：

[1] Rajiv Gandhi Ctr Biotechnol, Plant Dis Biol & Biotechnol, Thiruvananthapuram 695014, Kerala, India

[2] Univ Kerala, Res Ctr, Thiruvananthapuram 695034, India

[3] Sacred Heart Coll, Dept Bot, Kochi 682013, Kerala, India

[4] United Arab Emirates Univ, Dept Biol, Abu Dhabi 15551, U Arab Emirates

[5] John Innes Ctr, Dept Crop Genet, Norwich Res Pk, Norwich NR4 7UH, England

来源：

PLANT SCIENCE | 2024年 / 340卷

关键词：

Zingiber zerumbet; Zingiber officinale; Pythium myriotylum; Phenylalanine ammonia lyase; Lignin; Salicylic acid; QUANTITATIVE RESISTANCE; PHENOLIC-COMPOUNDS; GENE-EXPRESSION; PLANT-TISSUES; LIGNIN; DEFENSE; CONTRIBUTES; BIOSYNTHESIS; INFECTION; SUSCEPTIBILITY;

D O I：

10.1016/j.plantsci.2023.111972

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Little is known about the molecular basis of host defense in resistant wild species Zingiber zerumbet (L.) Smith against the soil -borne, necrotrophic oomycete pathogen Pythium myriotylum Drechsler, which causes the devastating soft rot disease in the spice crop ginger (Zingiber officinale Roscoe). We investigated the pattern of host defense between Z. zerumbet and ginger in response to P. myriotylum inoculation. Analysis of gene expression microarray data revealed enrichment of phenylpropanoid biosynthetic genes, particularly lignin biosynthesis genes, in pathogen -inoculated Z. zerumbet compared to ginger. RT-qPCR analysis showed the robust activation of phenylpropanoid biosynthesis genes in Z. zerumbet, including the core genes PAL, C4H, 4CL, and the monolignol biosynthesis and polymerization genes such as CCR, CAD, C3H, CCoAOMT, F5H, COMT, and LAC. Additionally, Z. zerumbet exhibited the accumulation of the phenolic acids including p-coumaric acid, sinapic acid, and ferulic acid that are characteristic of the cell walls of commelinoid monocots like Zingiberaceae and are involved in cell wall strengthening by cross linking with lignin. Z. zerumbet also had higher total lignin and total phenolics content compared to pathogen -inoculated ginger. Phloroglucinol staining revealed the enhanced fortification of cell walls in Z. zerumbet, specifically in xylem vessels and surrounding cells. The trypan blue staining indicated inhibition of pathogen growth in Z. zerumbet at the first leaf whorl, while ginger showed complete colonization of the pith within 36 h post inoculation (hpi). Accumulation of salicylic acid (SA) and induction of SA regulator NPR1 and the signaling marker PR1 were observed in Z. zerumbet. Silencing of PAL in Z. zerumbet through VIGS suppressed downstream genes, leading to reduced phenylpropanoid accumulation and SA level, resulting in the susceptibility of plants to P. myriotylum. These findings highlight the essential role of PAL -dependent mechanisms in resistance against P. myriotylum in Z. zerumbet. Moreover, our results suggest an unconventional role for SA in mediating host resistance against a necrotroph. Targeting the phenylpropanoid pathway could be a promising strategy for the effective management of P. myriotylum in ginger.

引用

页数：14