Identification and expression analysis of glucosinolate biosynthetic genes and estimation of glucosinolate contents in edible organs of Brassica oleracea subspecies

Go-Eun Yi; Arif Hasan Khan Robin; Kiwoung Yang; Jong-In Park; Jong-Goo Kang; Tae-Jin Yang; Ill-Sup Nou

doi:10.3390/molecules200713089

Identification and expression analysis of glucosinolate biosynthetic genes and estimation of glucosinolate contents in edible organs of Brassica oleracea subspecies

Molecules. 2015 Jul 20;20(7):13089-111. doi: 10.3390/molecules200713089.

Authors

Go-Eun Yi¹, Arif Hasan Khan Robin², Kiwoung Yang³, Jong-In Park⁴, Jong-Goo Kang⁵, Tae-Jin Yang⁶, Ill-Sup Nou⁷

Affiliations

¹ Department of Horticulture, Sunchon National University, Sunchon 540-950, Korea. yeege91@hanmail.net.
² Department of Horticulture, Sunchon National University, Sunchon 540-950, Korea. gpb21bau@gmail.com.
³ Department of Horticulture, Sunchon National University, Sunchon 540-950, Korea. ykw7685@naver.com.
⁴ Department of Horticulture, Sunchon National University, Sunchon 540-950, Korea. jipark@sunchon.ac.kr.
⁵ Department of Horticulture, Sunchon National University, Sunchon 540-950, Korea. jgkang@sunchon.ac.kr.
⁶ Department of Plant Science, Seoul National University, Seoul 151-742, Korea. tjyang@snu.ac.kr.
⁷ Department of Horticulture, Sunchon National University, Sunchon 540-950, Korea. nis@sunchon.ac.kr.

Abstract

Glucosinolates are anti-carcinogenic, anti-oxidative biochemical compounds that defend plants from insect and microbial attack. Glucosinolates are abundant in all cruciferous crops, including all vegetable and oilseed Brassica species. Here, we studied the expression of glucosinolate biosynthesis genes and determined glucosinolate contents in the edible organs of a total of 12 genotypes of Brassica oleracea: three genotypes each from cabbage, kale, kohlrabi and cauliflower subspecies. Among the 81 genes analyzed by RT-PCR, 19 are transcription factor-related, two different sets of 25 genes are involved in aliphatic and indolic biosynthesis pathways and the rest are breakdown-related. The expression of glucosinolate-related genes in the stems of kohlrabi was remarkably different compared to leaves of cabbage and kale and florets of cauliflower as only eight genes out of 81 were expressed in the stem tissues of kohlrabi. In the stem tissue of kohlrabi, only one aliphatic transcription factor-related gene, Bol036286 (MYB28) and one indolic transcription factor-related gene, Bol030761 (MYB51), were expressed. The results indicated the expression of all genes is not essential for glucosinolate biosynthesis. Using HPLC analysis, a total of 16 different types of glucosinolates were identified in four subspecies, nine of them were aliphatic, four of them were indolic and one was aromatic. Cauliflower florets measured the highest number of 14 glucosinolates. Among the aliphatic glucosinolates, only gluconapin was found in the florets of cauliflower. Glucoiberverin and glucobrassicanapin contents were the highest in the stems of kohlrabi. The indolic methoxyglucobrassicin and aromatic gluconasturtiin accounted for the highest content in the florets of cauliflower. A further detailed investigation and analyses is required to discern the precise roles of each of the genes for aliphatic and indolic glucosinolate biosynthesis in the edible organs.

Keywords: Brassica oleracea; biosynthetic genes; edible organs; expression analysis; glucosinolates; subspecies.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Brassica* / genetics
Brassica* / metabolism
Food Analysis
Gene Expression Regulation, Plant / physiology*
Glucosinolates* / analysis
Glucosinolates* / biosynthesis
Glucosinolates* / genetics
Transcription Factors* / genetics
Transcription Factors* / metabolism
Vegetables / chemistry
Vegetables / genetics
Vegetables / metabolism

Substances

Glucosinolates
Transcription Factors