VviSOC1a and VviAG1 act antagonistically in the regulation of flower formation

Epidermal Patterning Factors are a class of cysteine rich peptides known to be involved in many developmental processes. The role of EPF1, EPF2 and EPFL9 in controlling leaf stomata formation has been well described in model plants and cereals, and recently also in grapevine, while little is known about their activity in other organs. The aim of our study is to investigate whether VviEPFL9-2 can have a specific biological function in grapevine roots, where it resulted to be expressed. As grapevine is cultivated in the form of a grafted plant, we focused our study on the commonly used rootstock Kober 5BB (Vitis berlandieri x Vitis riparia). VviEPFL9-2 was edited in Kober 5BB plants using Agrobacterium tumefaciens transformation of embryogenic calli and the CRISPR/Cas9 technology. The phenotypic evaluation in greenhouse indicated that, as expected, the leaves of knock-out (KO) plants have a significant lower stomatal density compared to WT, associated with a lower stomatal conductance.

A multi-element pedo-geochemical survey was carried out in Vrbničko polje vineyards on the Krk Island, Croatia. This Mediterranean winegrowing site is famous by Žlahtina wine production.

Seedlessness is a key quality trait in table grapes. In Vitis vinifera, seedlessness can originate from different biological processes: parthenocarpy, the fruit formation without fertilization, or steno-spermocarpy, when fertilization occurs but is followed by aborted seed development.

In the O Ribeiro Denomination of Origin, there is a winemaking tradition of growing vines under a high-density plantation framework (8,920 vines/ha) and maintaining its vegetative cycle under rainfed conditions.
Currently, viticulture is advancing to plantation frames in which the density is considered medium (5,555 vines/ha), thus allowing mechanized work to be carried out for vineyard management operations. Although, the application of irrigation applied proportionally to the needs of the vegetative cycle of the vine, is a factor that increasingly helps a good development of the vine compared to the summer period, with increasingly uncertain weather forecasts.

Grapevines are useful model plants for research on the physiology of water stress responses. Variable responses at the stomatal level have been described in different varieties with implications on the hydraulic conductance of the plant and eventually impacts on the tension imposed to the xylem architecture, depending on xylem properties. In order to assess possible associations between stomatal responses (gs) to evaporative demand (VPD), water potentials at the root to leaf gradient, plant hydraulics and xylem morphoanatomical traits, a two-season research study has been conducted in Cabernet Sauvignon (CS), Carmenere (C) and Syrah (S) in the field, under mild water stress (MWS) and well watered (WW) conditions.