Molecular Cloning and Characterization of Three Glucosinolate Transporter (GTR) Genes from Chinese Kale.

Ding Jiang,Changming Chen,Jianjun Lei,Siyuan Wu,Bihao Cao,Guoju Chen

doi:10.3390/genes10030202

Abstract

Chinese kale is a native vegetable in Southern China and the flowering stalk is the most commonly used edible part due to its high glucosinolate content and other nutritional qualities. The GTR protein played important roles in the glucosinolate transport process. In this study, three BocGTR1 genes were cloned from Chinese kale for the first time. Their gene structure, physicochemical properties, signal peptides, transmembrane structures, functional domains, second and third-order protein structures, and phylogenetic relationships were predicted. The expression levels of BocGTR1a and BocGTR1c were much higher than those of BocGTR1b in various tissues, especially in leaves and buds. In addition, the expression patterns of three genes were examined under various abiotic stresses or hormone treatment, including those induced by wounding, heat stress, methyl jasmonate, salicylic acid, salt, and MgCl2 treatment. BocGTR1a and BocGTR1c were strongly induced by wounding and heat stress. The expression of BocGTR1a and BocGTR1c was significantly silenced in plants transformed by RNAi technology. Total glucosinolate content was significantly decreased in mature leaves and increased in roots of RNAi-transformed plants compared to wild-type plants. In addition, we found that BocGTR1a and BocGTR1c may participate in glucosinolate accumulation in different tissues with a selection for specific glucosinolates. These results indicated that BocGTR1a and BocGTR1c may be the key genes involved in the glucosinolate accumulation in different tissues of Chinese kale.

Highlights

Glucosinolates are a group of secondary metabolites containing nitrogen and sulfur, mainly found in the order Capparales
Andmax, C. sinensis were clustered in the third branch protein domain domain was predicted by Pfam and SMART, results indicated thatevery everyhomologous homologous sequence was predicted by Pfam and SMART, and and the the results indicated that sequence contained contained the the PTR2
Plants depend on their vast array of chemical weapons for defense against herbivores and pathogens, and these defense compounds accumulate to their highest levels in tissues that are most likely to be attacked [5,21]

Summary

Introduction

Glucosinolates are a group of secondary metabolites containing nitrogen and sulfur, mainly found in the order Capparales. These metabolites play important roles in plant defence and in human nutrition [1,2]. It has been clinically proven that some glucosinolate-derived isothiocyanate and nitrile compounds display anticarcinogenic activity [1,2]. Depending on the amino acids from which they are synthesized, glucosinolates are divided into three major groups: Aliphatic, indolyl, and aromatic glucosinolates [2]. The biosynthesis of glucosinolate occurs via three separate phases: The chain elongation of precursor amino acids, the formation of the core structure, and modifications of the side chain of glucosinolate [3]. A number of key regulators and genes involved in the biosynthetic

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Discussion

Conclusion