Morphology and Hydraulic Architecture of Vitis vinifera L. cv. Syrah and Torrontés Riojano Plants Are Unaffected by Variations in Red to Far-Red Ratio

GONZÁLEZ CARINA V.; JOFRÉ MARÍA FLORENCIA; VILA HERNÁN; STOFFEL MARKUS; BOTTINI RUBÉN; GIORDANO, CARLA V.

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2016

1932-6203

Plants have evolved an array of specificphotoreceptors to acclimate to the light environment. By sensing light signals,photoreceptors modulate plant morphology, carbon- and water-physiology, cropyield and quality of harvestable organs, among other responses. Many culturalpractices and crop management decisionsalter light quantity and qualityperceived by plants cultivated in the field. Under full sunlight,phytochromesperceive high red to far red ratios (R:FR; 1.1), whereas overhead or laterallow R:FR (below 1.1) are sensed in the presence of plant shade or neighboringplants, respectively. Grapevine is one of the most important fruit crops in theworld. To date, studies on grapevine response to light focused on different PhotosyntheticActive Radiation (PAR) levels, however limited data exist about its response tolight quality. In this study we aimedto investigate morphological, biochemical,and hydraulic responses of Vitisvinifera to variations in R:FR. Therefore,we irradiated Syrah and TorrontésRiojanoplants, grown in a glasshouse, withlateral FR light (low lateral R:FR treatment), while others, that were kept ascontrols, were not irradiated(ambient lateral R:FR treatment). In response tothe low lateral R:FR treatment,grapevine plants did not display any of the SASmorphological markers (i.e. stem length, petiole length and angle, number oflateral shoots) in anyof the cultivars assessed,despite an increase ingibberelins and auxin concentrations in leaf tissues. Low lateral R:FR did not affectdry matter partitioning, water-related traits (stomata density and index, woodanatomy), or water-related physiology (plant conductance, transpiration rate,stem hydraulic conductivity, stomatal conductance). None of the Vitisviniferavarieties assessed displayedtheclassical morphological and hydraulic responses associated to SAS induced byphytochromes. We discuss these results in the context ofnatural grapevineenvironment and agronomical relevance