Abstract

BackgroundThe rich yellow-orange to vividly deep red bark of willow (Salix spp.) branches have high ornamental and economic value. However, the mechanism underlying the regulation of willow branch color remains unknown. Therefore, we performed metabolomics and transcriptomics analyses of purple, green, and red willow barks to elucidating the mechanisms regulating color development.ResultsSeven anthocyanins were isolated; pelargonidin, petunidin 3-O-rutinoside, and cyanin chloride were the most abundant in red bark, whereas pelargonin chloride was most abundant in purple bark. The green bark contained the highest level of malvidin; however, the malvidin level was not significantly higher than in the red bark. The purple bark contained the largest amount of canthaxanthin, a carotenoid pigment. The integrated pathways of flavonoid biosynthesis, carotenoid biosynthesis, and porphyrin and chlorophyll metabolism were constructed for the willow barks. Among the three barks, the expression of the structural genes ANS, ANR, and BZ1, which are involved in anthocyanin synthesis, was the highest in red bark, likely causing anthocyanin accumulation. The expression of CrtZ, which participates in the carotenoid pathway, was the highest in purple bark, likely leading to canthaxanthin accumulation. The high expression of DVR, POR, and CRD1 may be associated with green pigment synthesis in the chlorophyll biosynthesis pathway.ConclusionsPurple bark color is co-regulated by anthocyanins and carotenoids, whereas red bark is characterized by anthocyanin accumulation and chlorophyll degradation. The green pigment is regulated by maintaining chlorophyll synthesis. BZ1 and CrtZ are candidate genes regulating anthocyanin and canthaxanthin accumulation in red and purple barks respectively. Collectively, our results may facilitate the genetic breeding and cultivation of colorful willows with improved color and luster.

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 call

Disclaimer: 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.