Abscisic acid (ABA) and gibberellic acid (GA) are regulators of fruit color and sugar levels, and the application of these hormones is a common practice in commercial vineyards dedicated to the production of table grapes. However, the effects of exogenous ABA and GA on wine cultivars remain unclear. We investigated the impact of ABA and GA application on Malbec grapevine berries across three developmental stages.
View Article and Find Full Text PDFSalinity is one of the principal abiotic stresses that limit the growth and productivity of crops. The use of halotolerant plant growth-promoting rhizobacteria (PGPR) that increase the growth of salt-stressed crops is an environmentally friendly alternative to promote plant yield under salinity. The aim of this study was to test native PGPR, isolated according to their tolerance to NaCl, and to evaluate their influence on morphological, physiological, and biochemical traits promoted by salt stress in tomato plants.
View Article and Find Full Text PDFPlants are able to synthesize a large number of organic compounds. Among them, primary metabolites are known to participate in plant growth and development, whereas secondary metabolites are mostly involved in defense and other facultative processes. In grapevine, one of the major fruit crops in the world, secondary metabolites, mainly polyphenols, are of great interest for the wine industry.
View Article and Find Full Text PDFGrape quality for winemaking depends on sugar accumulation and metabolism in berries. Abscisic acid (ABA) and gibberellins (GAs) have been reported to control sugar allocation in economically important crops, although the mechanisms involved are still unknown. The present study tested if ABA and gibberellin A3 (GA3) enhance carbon allocation in fruits of grapevines by modifying phloem loading, phloem area and expression of sugar transporters in leaves and berries.
View Article and Find Full Text PDFThis study investigated terpene biosynthesis in different tissues (root, protobulb, leaf sheath and blade) of in vitro-grown garlic plants either infected or not (control) with Sclerotium cepivorum, the causative agent of Allium White Rot disease. The terpenes identified by gas chromatography-electron impact mass spectrometry (GC-EIMS) in infected plants were nerolidol, phytol, squalene, α-pinene, terpinolene, limonene, 1,8-cineole and γ-terpinene, whose levels significantly increased when exposed to the fungus. Consistent with this, an increase in terpene synthase (TPS) activity was measured in infected plants.
View Article and Find Full Text PDFProduction of phytohormones is one of the main mechanisms to explain the beneficial effects of plant growth-promoting rhizobacteria (PGPR) such as Azospirillum sp. The PGPRs induce plant growth and development, and reduce stress susceptibility. However, little is known regarding the stress-related phytohormone abscisic acid (ABA) produced by bacteria.
View Article and Find Full Text PDFUltraviolet-B solar radiation (UV-B) is an environmental signal with biological effects in plant tissues. Recent investigations have assigned a protective role of volatile organic compounds (VOCs) in plant tissues submitted to biotic and abiotic stresses. This study investigated VOCs in berries at three developmental stages (veraison, pre-harvest and harvest) of Vitis vinifera L.
View Article and Find Full Text PDFThis study investigated the terpene profiles as determined by GC-EIMS analysis of in vitro cultured plants of Vitis vinifera exposed to a "field-like" dose of UV-B (4.75 kJ m(-2)d(-1)) administered at two different fluence rates (low, 16 h at 8.25 μW cm(-2), and high 4 h at 33 μW cm(-2)).
View Article and Find Full Text PDFBackground: Ultraviolet-B radiation (UV-B, 280-315 nm) is a natural component of sunlight, which has numerous regulatory effects on plant physiology. The nature of the response to UV-B is dependent on fluence rate, dose, duration and wavelength of the UV-B treatment. Some reports have analyzed the changes in gene expression caused by UV-B light on several plant species using microarray technology.
View Article and Find Full Text PDFCell elongation during seedling development is antagonistically regulated by light and gibberellins (GAs). Light induces photomorphogenesis, leading to inhibition of hypocotyl growth, whereas GAs promote etiolated growth, characterized by increased hypocotyl elongation. The mechanism underlying this antagonistic interaction remains unclear.
View Article and Find Full Text PDFBlue light inhibits elongation of etiolated Arabidopsis thaliana hypocotyls during the first 30 min of irradiation by a mechanism that depends on the phototropin 1 (phot1) photoreceptor. The cryptochrome 1 (cry1) photoreceptor begins to exert control after 30 min. To identify genes responsible for the cry1 phase of growth inhibition, mRNA expression profiles of cry1 and wild-type seedlings were compared using DNA microarrays.
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