Abbreviations: Gα, α-subunit of heterotrimeric G-protein; PKC, protein kinase C; PLD, phospholipase D; PtdIns(4,5)P 2 , phosphatidylinositol-4,5-bisphosphate. * To whom correspondence should be addressed.Abstract⎯Phospholipase D (PLD) catalyzes hydrolysis of phospholipids with production of phosphatidic acids, which often act as secondary messengers on transmission of intracellular signals. This review summarizes data of various leading laboratories on specific features of organization and regulation of PLD activity in plant and animal cells. The main structural domains of PLD (C2, PX, PH), the active site, and other functionally important parts of the enzyme are considered. Regulatory mechanisms of PLD activity are characterized in detail. Studies associated with molecular design, analysis, and synthesis of new nontoxic substances capable of inhibiting different PLD isoenzymes in vivo are shown to be promising for biotechnology and medicine.

Gravity is one of the environmental cues that direct plant growth and development. Recent investigations of different gravity signalling pathways have added complexity to how we think gravity is perceived. Particular cells within specific organs or tissues perceive gravity stimulus. Many downstream signalling events transmit the perceived information into subcellular, biochemical, and genomic responses. They are rapid, non-genomic, regulatory, and cell-specific. The chain of events may pass by signalling lipids, the cytoskeleton, intracellular calcium levels, protein phosphorylation-dependent pathways, proteome changes, membrane transport, vacuolar biogenesis mechanisms, or nuclear events. These events culminate in changes in gene expression and auxin lateral redistribution in gravity response sites. The possible integration of these signalling events with amyloplast movements or with other perception mechanisms is discussed. Further investigation is needed to understand how plants coordinate mechanisms and signals to sense this important physical factor.

No abstract

No abstract

Due to the increasing demand for biofuel production, it is an important goal to optimize the seed productivity and quality of oilseed plants even in adverse conditions. Acting on signalling mechanisms might provide means to attain such goals. In this study, we were interested in the effect of a brassinosteroid hormone 24-epibrassinolide (24-EBR) on Brassica napus cultivated in salt stress condition. We show that salt stress leads to a 60 % decrease in seed production in B. napus. This is accompanied by a 50 % decrease in seed oil content. Treatment with 24-EBR had no effect on seed and oil productivity in control plants. However, it could rescue half of the seed production and all the oil production in salt-treated plants. The fatty acid composition of seed oil in B. napus was selectively affected by salt stress, 24-EBR or combined treatment. Besides these long-term actions of 24-EBR, we have also investigated its short-term actions in cell signalling. We did so by in vivo labelling of plantlets with fluorescently labelled phosphatidylcholine. A treatment of 2 h with 24-EBR was sufficient to induce a substantial increase in the content of diacylglycerol and phosphatidic acid, two lipid mediators. Nonspecific phospholipases C and phospholipases D are involved in these increases. Therefore, brassinosteroid treatments appear as promising way to gain oil productivity when plants have to grow in unfavourable conditions such as salt stress. The link between long-term actions and shortterm signalling of 24-EBR is discussed. Keywords 24-Epibrassinolide Á Oil productivity Á Salt stress Á Fatty acids Á Phospholipase D Á Nonspecific phospholipase C Electronic supplementary material The online version of this article (

Aim. To investigate 24-epibrassinolide influence on the maize seedlings

No abstract

The review is devoted to the analysis of publications ñoncerning the role of phospholipase D (PLD) in regulation of metabolism in plant cells. Analysis of molecular and genetic studies suggest that PLD is an important component of various hormonal and stress signaling pathway