Differences among the Anthocyanin Accumulation Patterns and Related Gene Expression Levels in Red Pears.

Meng Wu,Zhuo Liu,Jianlong Liu,Xieyu Li,Zhigang Wang,Liu Cong,Linyan Song,Lingfei Xu,Rongrong Yue,Chengquan Yang

doi:10.3390/plants8040100

Abstract

Differences in coloration exist among red pear cultivars. Here, we selected six red pear cultivars with different genetic backgrounds to elucidate the characteristics of fruit pigmentation. We detected anthocyanin contents and the expression levels of anthocyanin synthesis-related genes in these cultivars at different stages of fruit development. The anthocyanin contents of all six cultivars showed a rise–drop tendency. Principal component and hierarchical cluster analyses were used to distinguish the types of cultivars and the genes crucial to each anthocyanin accumulation pattern. The six cultivars were divided into three groups. Red Zaosu were clustered into one group, Red Sichou and Starkrimson into another group, and Palacer, Red Bartlett, and 5 Hao clustered into a third group. The expression levels of F3H, UFGT2, MYB10, and bHLH3 were similar among the differential coloration patterns of the six cultivars, suggesting a critical and coordinated mechanism for anthocyanin synthesis. Anthocyanin transporters (GST) and light-responsive genes, such as COP1, PIF3.1, and PIF3.2 played limited roles in the regulation of anthocyanin accumulation. This study provides novel insights into the regulation of anthocyanins synthesis and accumulation in red pears.

Highlights

To study the different coloring patterns of the red pear cultivars, we investigated the different stages of fruit development in six cultivars, 5 Hao, ‘Red Zaosu’, Red Sichou, Palacer, Starkrimson and Red Bartlett
The peak accumulations of anthocyanin in all of the cultivars occurred during the middle stages of fruit development
The different expression levels of the structural genes F3H and UFGT2 were important for anthocyanin accumulation in the six cultivars

Summary

Introduction

The color of the pear is an important factor in consumer acceptance of fresh pears. Pears show different coloring patterns owing to different genetic backgrounds. There are four major pear classifications in the world, including the Asian pear species (Pyrus pyrifolia, Pyrus bretschneideri, and Pyrus ussuriensis) and European pear species (Pyrus communis). Red pears are mostly classified as European pears, while the coloration of most. Asian pear cultivars ranges from yellow-green to brown, with a few being red [1]. Little is known about the coloring mechanisms of different red pear cultivars. It is important to study the mechanisms responsible for the different coloring patterns of red pears

Objectives

Methods

Results

Discussion

Conclusion