Peach is one of the most economically important fruit crops worldwide, which is characterized by fuzzy skin due to the presence of trichome, while nectarine, as the subspecies of peach, is absent of trichome.

A fuzzy gene PpMYB25 has been proven to be a candidate for the G locus controlling the trichome in peach fruit. However, the underlying regulatory mechanism of PpMYB25 to fruit cuticle is far from known.

Supervised by Prof. HAN Yuepeng of Wuhan Botanical Garden, Ph.D. student YANG Qiurui compared the difference between peach and nectarine fruit cuticle by SEM (scanning electron microscope) and GC (gas chromatography), and found that not only trichome, the structure and content of cuticle wax also had a great deal of variation.

A series of studies such as transgenic and molecular biology experiments showed that PpMYB25 and its downstream homolog PpMYB26 not only controlled fruit trichome formation, but also participated in the regulation of cuticular wax accumulation through activating transcription of cuticular wax biosynthetic genes.

Inactivation of PpMYB25 and PpMYB26 causes the failure of trichome formation and a reduction in cuticular wax accumulation, resulting in the fuzzless and glossy fruit trait of nectarine.

This study unveils the transcriptional regulatory networks controlling fruit trichome initiation and cuticular wax biosynthesis in peach and enlightens molecular mechanisms underlying the origin of nectarine.

This work was published in New Phytologist entitled “TwoR2R3-MYBgenes cooperatively control trichome development and cuticular wax biosynthesis inPrunus persica”.

The regulatory network model of PpMYB25 and PpMYB26 in trichome and cuticular wax of peach fruit (Image by YANG Qiurui)