Abstract
To elucidate the effect of low temperature on anthocyanin biosynthesis in purple head Chinese cabbage, we analyzed anthocyanin accumulation and related gene expression in the seedlings of purple head Chinese cabbage, white head parent Chinese cabbage, and its purple male parent under a normal 25 °C temperature and a low 12 °C temperature. Anthocyanin accumulation in purple lines was strongly induced by low temperature, and the total anthocyanin content of seedlings was significantly enhanced. In addition, nearly all phenylpropanoid metabolic pathway genes (PMPGs) were down-regulated, some early biosynthesis genes (EBGs) were up-regulated, and nearly all late biosynthesis genes (LBGs) directly involved in anthocyanin biosynthesis showed higher expression levels in purple lines after low-temperature induction. Interestingly, a R2R3-MYB transcription factor (TF) gene ‘BrMYB2’ and a basic-helix-loop-helix (bHLH) regulatory gene ‘BrTT8’ were highly up-regulated in purple lines after low temperature induction, and two negative regulatory genes ‘BrMYBL2.1’ and ‘BrLBD38.2’ were up-regulated in the white line. BrMYB2 and BrTT8 may play important roles in co-activating the anthocyanin structural genes in purple head Chinese cabbage after low-temperature induction, whereas down-regulation of BrMYB2 and up-regulation of some negative regulators might be responsible for white head phenotype formation. Data presented here provide new understanding into the anthocyanin biosynthesis mechanism during low temperature exposure in Brassica crops.
Highlights
Anthocyanin is a water-soluble pigment of the flavonoid family in plant secondary metabolism, and is responsible for gorgeous coloration and stress resistance in fruits and vegetables [1]
12 ◦ C -treatment in Line95T, but it was only induced in midrib in Line11S (Figure 5I and Table S1). These results indicated that the R2R3-MYB regulator gene BrMYB2 and BrTT8 might be active and induced by low temperature during anthocyanin biosynthesis in purple head Chinese cabbage and its purple trait donor, but BrMYB2 played a key role in the anthocyanin accumulation
We performed a transcriptional analysis of 86 anthotyanin biosynthesis genes in leaves and midribs from Chinese cabbage seedlings grown at room temperature (25 ◦ C) and low temperature (12 ◦ C) to identify genes involved in the mechanism of anthocyanin accumulation
Summary
Anthocyanin is a water-soluble pigment of the flavonoid family in plant secondary metabolism, and is responsible for gorgeous coloration and stress resistance in fruits and vegetables [1]. Anthocyanin biosynthesis is one of the most widely studied secondary metabolic pathways in plants, and the genetic and biochemical study of anthocyanin metabolism focused on the understanding of regulation has generated significant scientific breakthroughs [4]. The primary phenylpropanoid metabolic pathway provides components for subsequent flavonoid and ligin biosynthesis [5] consisting of phenylalanine ammonia lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate: CoA ligase (4CL). PAL, which is regarded as the key rate-limiting enzyme in this step, catalyzes the biotransformation of L-phenylalanine into trans-cinnamic acid, and it is catalyzed by C4H into p-coumaric acid [5].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
