The Teng Yuanwen/Bai Songling team of Zhejiang University made progress in the study of the regulatory mechanism of light-induced pear peel anthocyanin synthesis

Pears belong to the Rosaceae family (Rosaceae) and are the most important temperate deciduous fruit trees
in the world.
Pear peel color is diverse, usually cultivated pear varieties are brown, yellow, yellow-green, etc.
, in recent years the cultivation of red (peel) pear gradually increased, the formation of red pear color mainly from the accumulation
of anthocyanins in the peel.
Anthocyanins are an important secondary metabolite, which largely determine the color, nutrition, antioxidant and other qualities of fruits, so it is of great scientific value
to study the regulatory mechanism of anthocyanin synthesis in pear peel.
The synthesis of anthocyanins is regulated by genetic factors, environmental factors and growth and development factors, among which light is one of the most important environmental factors regulating the synthesis of anthocyanins in fruits, but its regulatory mechanism is not fully understood
.

Recently, Horticulture Research launched a report entitled Light-responsive transcription factor PpWRKY44 induces anthocyanin accumulation by regulating PpMYB10 on the launch of Advance Access Research paper
on expression in pear.
This paper reveals a molecular mechanism
by which WRKY transcription factor PpWRKY44 promotes the synthesis of anthocyanins in pear peel by regulating the expression of PpMYB10 in response to illumination.

The study screened through pre-transcriptome data to obtain a WRKY transcription factor that responds positively to the light signal, PpWRKY44
.
The authors confirmed the function
of PpWRKY44 in inducing anthocyanin synthesis through the callus transgene of 'nightshade pear', transient overexpression/silencing of pear peel and transient overexpression of leaves of autumn pear.
The authors further used ChIP-qPCR, EMSA, yeast single hybridization, and double luciferase assays to find that PpWRKY44 activated its expression by directly binding to the W-box on the PpMYB10 promoter, thereby inducing anthocyanin synthesis
.
In addition, this study also found that PpWRKY44 was activated
by the transcription factor PpBBX18 (Bai et al.
, 2019), which was previously identified by the group.
In summary, this study reveals the regulatory pathway of photo-PpBBX18-PpWRKY44-PpMYB10-anthocyanin synthesis, and the results enrich the regulatory network of pear anthocyanin synthesis and provide new ideas
for improving the appearance and quality of fruits.

Fig.
1 Transient overexpression of 'nightshade' callus transgene and leaves of autumn pear showed that PpWRKY44 induced anthocyanin synthesis

Fig.
2 Light-induced PpWRKY44 model for inducing anthocyanin synthesis of pear peel by regulating PpMYB10

Ahmed Alabd, a doctoral student at the College of Agriculture and Biotechnology, Zhejiang University, is the first author of the paper, and Professor Teng Yuanwen and researcher Bai Songling are the co-corresponding authors
of the paper.
The research was supported
by the National Natural Science Foundation of China, the National Modern Agriculture (Pear) Industrial Technology System Special Fund, and the Basic Research Project of Central Universities.

Article link: https://doi.
org/10.
1093/hr/uhac199