Comparative Study of Bolting Adaptability between 60Co-Induced Rape and Its Original Material

Abstract

In southern China, the fresh shoots of rape are used as a high-quality seasonal vegetable owing to their pleasant taste. In this study, we investigated the taste and quality of fresh shoots of Fanmingyoutai, which was derived from WH23 by 60Co mutation. WH23 was used as a control (CK). Physiological indexes, transcriptome analyses, and metabolomics analyses between Fanmingyoutai and CK were studied and the related key differential genes were identified. The results showed that the glucosinolate content of Fanmingyoutai seeds was 51.14% lower than that of CK, and the contents of soluble sugar and vitamin C in the fresh shoots of Fanmingyoutai were 2.1 times and 1.4 times higher, respectively, than CK. Using transcriptome analyses, we identified that the differential genes were involved in glycan biosynthesis and metabolism, energy metabolism, carbohydrate metabolism, and the metabolism of cofactors and vitamins. Metabolomics analyses demonstrated that the contents of sucrose and D-fructose in the fresh shoots of Fanmingyoutai were 1.22 times and 1.15 times higher, respectively, than those in CK. Using qRT-PCR analyses, the expression of SWEET17, STP5, and GSL in the fresh shoots and leaves of Fanmingyoutai was two times higher than that in CK. SWEET17 (involved in sugar production and transport), STP5 (involved in monosaccharide transport), and GSL (involved in glucosinolate accumulation) may be the key functional genes. We concluded that the low glucosinolate content and high sucrose and D-fructose contents may be the main factors affecting the taste of fresh shoots of Fanmingyoutai and CK; SWEET17, STP5, and GSL may be the key related genes. This research provides a reference for the breeding and molecular mechanisms of new edible rape varieties.