Glucosinolates （GSs） are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid （JA） and salicylic acid （SA） are major regulators of plant response to pathogen ...Glucosinolates （GSs） are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid （JA） and salicylic acid （SA） are major regulators of plant response to pathogen attack. However, there is little information about the interactive effect of both elicitors on inducing GS biosynthesis in Chinese cabbage （Brassica rapa ssp. pekinensis）. In this study, we applied different concentrations of methyl jasmonate （MeJA） and/or SA onto the leaf and root of Chinese cabbage to investigate the time-course interactive profiles of GSs. Re- gardless of the site of the elicitation and the concentrations of the elicitors, the roots accumulated much more GSs and were more sensitive and more rapidly responsive to the elicitors than leaves. Irrespective of the elicitation site, MeJA had a greater inducing and longer lasting effect on GS accumulation than SA. All three components of indole GS （IGS） were detected along with aliphatic and aromatic GSs. However, IGS was a major component of total GSs that ac- cumulated rapidly in both root and leaf tissues in response to MeJA and SA elicitation. Neoglucobrassicin （neoGBC） did not respond to SA but to MeJA in leaf tissue, while it responded to both SA and MeJA in root tissue. Conversion of glucobrassicin （GBC） to neoGBC occurred at a steady rate over 3 d of elicitation. Increased accumulation of 4-methoxy glucobrassicin （4-MGBC） occurred only in the root irrespective of the type of elicitors and the site of elici- tation. Thus, accumulation of IGS is a major metabolic hallmark of SA＊ and MeJA-mediated systemic response sys- tems. SA exerted an antagonistic effect on the MeJA-induced root GSs irrespective of the site of elicitation. However, SA showed synergistic and antagonistic effects on the MeJA-induced leaf GSs when roots and leaves are elicitated for 3 d, respectively.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31000916 and 30871718)the Zhejiang Provincial Natural Science Foundation of China(Nos.LY14C150005,LZ14C150001,and Y3090538)+3 种基金the Scientific Research Starting Foundation for the Returned Overseas Chinese Scholars from the Ministry of Education of Chinathe Climbing Program for Young Academic Leaders in Universities of Zhejiang Province(No.pd2013230)the Qianjiang Talent Project of Zhejiang Province(No.qjd0902010)the Key Sci-Technology Project of Zhejiang Province(No.2010C12004),China
文摘Glucosinolates （GSs） are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid （JA） and salicylic acid （SA） are major regulators of plant response to pathogen attack. However, there is little information about the interactive effect of both elicitors on inducing GS biosynthesis in Chinese cabbage （Brassica rapa ssp. pekinensis）. In this study, we applied different concentrations of methyl jasmonate （MeJA） and/or SA onto the leaf and root of Chinese cabbage to investigate the time-course interactive profiles of GSs. Re- gardless of the site of the elicitation and the concentrations of the elicitors, the roots accumulated much more GSs and were more sensitive and more rapidly responsive to the elicitors than leaves. Irrespective of the elicitation site, MeJA had a greater inducing and longer lasting effect on GS accumulation than SA. All three components of indole GS （IGS） were detected along with aliphatic and aromatic GSs. However, IGS was a major component of total GSs that ac- cumulated rapidly in both root and leaf tissues in response to MeJA and SA elicitation. Neoglucobrassicin （neoGBC） did not respond to SA but to MeJA in leaf tissue, while it responded to both SA and MeJA in root tissue. Conversion of glucobrassicin （GBC） to neoGBC occurred at a steady rate over 3 d of elicitation. Increased accumulation of 4-methoxy glucobrassicin （4-MGBC） occurred only in the root irrespective of the type of elicitors and the site of elici- tation. Thus, accumulation of IGS is a major metabolic hallmark of SA＊ and MeJA-mediated systemic response sys- tems. SA exerted an antagonistic effect on the MeJA-induced root GSs irrespective of the site of elicitation. However, SA showed synergistic and antagonistic effects on the MeJA-induced leaf GSs when roots and leaves are elicitated for 3 d, respectively.
