Rootstock effects on scion phenotypes in a \u2018Chambourcin\u2019 experimental vineyard

Zoë Migicovsky,Laura L Klein,Misha Kwasniewski,Mao Li,Allison J Miller,Laszlo G Kovacs,Daniel H Chitwood,Jason P Londo,Adam Mcdermaid,Zachary N Harris,Anne Fennell,Qin Ma

doi:10.1038/s41438-019-0146-2

Abstract

Understanding how root systems modulate shoot system phenotypes is a fundamental question in plant biology and will be useful in developing resilient agricultural crops. Grafting is a common horticultural practice that joins the roots (rootstock) of one plant to the shoot (scion) of another, providing an excellent method for investigating how these two organ systems affect each other. In this study, we used the French-American hybrid grapevine ‘Chambourcin’ (Vitis L.) as a model to explore the rootstock–scion relationship. We examined leaf shape, ion concentrations, and gene expression in ‘Chambourcin’ grown ungrafted as well as grafted to three different rootstocks (‘SO4’, ‘1103P’ and ‘3309C’) across 2 years and three different irrigation treatments. We found that a significant amount of the variation in leaf shape could be explained by the interaction between rootstock and irrigation. For ion concentrations, the primary source of variation identified was the position of a leaf in a shoot, although rootstock and rootstock by irrigation interaction also explained a significant amount of variation for most ions. Lastly, we found rootstock-specific patterns of gene expression in grafted plants when compared to ungrafted vines. Thus, our work reveals the subtle and complex effect of grafting on ‘Chambourcin’ leaf morphology, ionomics, and gene expression.

Highlights

Root and shoot systems operate in dramatically different environments and provide unique roles within a plant
Using comprehensive leaf shape analysis, leaf ion concentrations, and patterns of gene expression, we evaluated whether these scion traits are altered by use of rootstocks
Leaf shape assessed using shape descriptors We examined whether a significant amount of the variation in simple shape descriptors, used to describe leaf morphology, could be explained by block, rootstock, year of sampling (2014 or 2016), irrigation treatment from the prior year and the interaction between rootstock and irrigation (Fig. 1a, Table S1)

Summary

Introduction

Root and shoot systems operate in dramatically different environments and provide unique roles within a plant. These functionally distinct below- and above-ground parts are inextricably linked at the organismal level. A further understanding of this interaction has important agricultural implications, since selection for traits like root architecture and physiology can enhance stress tolerance and yield[1]. In over 70 major crops, selection for root and shoot system traits have been decoupled through the process of grafting. Beyond its practical implications, grafting offers an unique opportunity to independently manipulate parts of the plant to understand how roots impact shoots, and vice versa

Methods

Results

Discussion

Conclusion