Promoting effect of foliage sprayed zinc sulfate on accumulation of sugar and phenolics in berries of Vitis vinifera cv. Merlot growing on zinc deficient soil.

Chang-Zheng Song,Zhen-Wen Zhang,Ming Chi,Mei-Ying Liu,Jiang-Fei Meng,Zhu-Mei Xi

doi:10.3390/molecules20022536

Chang-Zheng Song, Zhen-Wen Zhang + Show 4 more

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https://doi.org/10.3390/molecules20022536

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Abstract

The effect of foliage sprayed zinc sulfate on berry development of Vitis vinifera cv. Merlot growing on arid zone Zn-deficient soils was investigated over two consecutive seasons, 2013 and 2014. Initial zinc concentration in soil and vines, photosynthesis at three berry developmental stages, berry weight, content of total soluble solids, titratable acidity, phenolics and expression of phenolics biosynthetic pathway genes throughout the stages were measured. Foliage sprayed zinc sulfate showed promoting effects on photosynthesis and berry development of vines and the promotion mainly occurred from veraison to maturation. Zn treatments enhanced the accumulation of total soluble solids, total phenols, flavonoids, flavanols, tannins and anthocyanins in berry skin, decreasing the concentration of titratable acidity. Furthermore, foliage sprayed zinc sulfate could significantly influence the expression of phenolics biosynthetic pathway genes throughout berry development, and the results of expression analysis supported the promotion of Zn treatments on phenolics accumulation. This research is the first comprehensive and detailed study about the effect of foliage sprayed Zn fertilizer on grape berry development, phenolics accumulation and gene expression in berry skin, providing a basis for improving the quality of grape and wine in Zn-deficient areas.

Highlights

Zinc (Zn) is an essential micronutrient for the normal healthy growth and reproduction of plants, animals and humans [1]
Concentrations of available N, P, K and Cu were all within the normal range, while those of Zn, Fe and Mn were lower than the critical values
Combined with the analysis of gene expression at 61 days after flowering (DAF), the results suggested that the promotion of phenolic compound biosynthesis in Zn application groups could be caused by the higher expression of genes in phenolics biosynthetic pathway at veraison

Summary

Introduction

Zinc (Zn) is an essential micronutrient for the normal healthy growth and reproduction of plants, animals and humans [1]. Zn plays a key role as a structural constituent or regulatory co-factor of a wide range of different enzymes and proteins in many important biochemical pathways. These roles include carbohydrate metabolism (both in photosynthesis and in the conversion of sugars to starch), protein metabolism, auxin (growth regulator) metabolism, pollen formation, the maintenance of the integrity of biological membranes, the resistance to infection by certain pathogens [2,3]. Many important physiological functions of Zn are unable to operate normally in Zn-deficient plants, and plant growth would be adversely affected [4].

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