Expression analysis of key genes of phenylpropanoid pathway and phenol profiling during Ricinus communis–Fusarium oxysporum f. sp. ricini interaction

• Published in: Industrial crops and products Vol. 50; pp. 456 - 461
• Main Authors: Jadhav, Pritam R., Mahatma, Mahesh K., Mahatma, Lalit, Jha, Sanjay, Parekh, Vipul B., Khandelwal, Vikas
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2013
• Subjects: caffeic acid; Castor, HPTLC, RT-PCR, Phenolics, Wilt; disease resistance; ferulic acid; gene expression regulation; genes; genotype; phenol; phenylalanine ammonia-lyase; reverse transcriptase polymerase chain reaction; Ricinus; salicylic acid; secondary metabolites; trans-cinnamate 4-monooxygenase; wilting; Castor, HPTLC, RT-PCR, Phenolics, Wilt
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2013.08.022

•Expression analysis of phenylalanine ammonia lyase (PAL) and cinnamate 4-hydroxylase (C4H) genes in castor revealed that the expression of PAL and C4H-2 gene increased in resistant genotypes at 48h interval of infection of wilt pathogen than compared to susceptible genotype.•Expression of gene C4H-1 was down regulated in susceptible genotypes after 24 and 48h.a.i. while in resistant genotypes it was up regulated.•Phenol profiling using HPTLC showed that higher content of caffeic and ferulic acid was detected in infected and non infected resistant genotypes at 0, 24 and 48h.a.i. The general phenylpropanoid metabolism generates an array of secondary metabolites and phenolic acids which imparts disease resistance in plants. Expression pattern of the key genes of phenylpropanoid pathway was studied at 0, 24 and 48h after infection (h.a.i.) and phenolic acid profiling was carried out at 0, 24, 48 and 72h.a.i. in the leaves of wilt infected and non- infected of both resistant and susceptible genotypes of castor. Expression analysis of PAL (phenylalanine ammonia lyase), C4H1 (cinnamate 4-hydroxylase 1) and C4H2 (cinnamate 4-hydroxylase 2) genes using RT-PCR with gene specific primers showed appreciable increase in the expression of PAL and C4H-2 gene in resistant genotypes at 48h interval than 24h interval compared to susceptible genotype. However, gene C4H-1 was down regulated in susceptible genotypes after 24 and 48h.a.i. while up regulated in resistant genotypes. Phenol profiling using HPTLC showed the presence of three phenolic acids i.e. caffeic acid, ferulic acid and salicylic acid in non-infected and infected castor genotypes. Higher content of caffeic and ferulic acid was detected in infected and non-infected resistant genotypes at 0, 24 and 48h.a.i, whereas caffeic acid was not detected in susceptible genotypes at 0h.a.i. These results suggest the critical role of phenols in castor disease resistance.