Differential Activation of Partially Redundant Δ9 Stearoyl-ACP Desaturase Genes Is Critical for Omega-9 Monounsaturated Fatty Acid Biosynthesis During Seed Development in Arabidopsis.

The spatiotemporal pattern of deposition, final amount, and relative abundance of oleic acid (-ω-9 C18:1) and its derivatives in the different lipid fractions of the seed of Arabidopsis () indicates that omega-9 monoenes are synthesized at high rates in this organ. Accordingly, we observed that four Δ9 stearoyl-ACP desaturase (SAD)-coding genes ( [], [], , and ) are transcriptionally induced in seeds. We established that the three most highly expressed ones are directly activated by the WRINKLED1 transcription factor.

Deposition of a cutin apoplastic barrier separating seed maternal and zygotic tissues.

Background: In flowering plants, proper seed development is achieved through the constant interplay of fertilization products, embryo and endosperm, and maternal tissues. Communication between these compartments is supposed to be tightly regulated at their interfaces. Here, we characterize the deposition pattern of an apoplastic lipid barrier between the maternal inner integument and fertilization products in Arabidopsis thaliana seeds.

Phospholipases Dζ1 and Dζ2 have distinct roles in growth and antioxidant systems in Arabidopsis thaliana responding to salt stress.

Phospholipases Dζ play different roles in Arabidopsis salt tolerance affecting the regulation of ion transport and antioxidant responses. Lipid signalling mediated by phospholipase D (PLD) plays essential roles in plant growth including stress and hormonal responses. Here we show that PLDζ1 and PLDζ2 have distinct effects on Arabidopsis responses to salinity.

Developmental patterning of the sub-epidermal integument cell layer in seeds.

Angiosperm seed development is a paradigm of tissue cross-talk. Proper seed formation requires spatial and temporal coordination of the fertilization products - embryo and endosperm - and the surrounding seed coat maternal tissue. In early seed development, all seed integuments were thought to respond homogenously to endosperm growth.

Involvement of Phosphatidylinositol 3-kinase in the regulation of proline catabolism in Arabidopsis thaliana.

Plant adaptation to abiotic stresses such as drought and salinity involves complex regulatory processes. Deciphering the signaling components that are involved in stress signal transduction and cellular responses is of importance to understand how plants cope with salt stress. Accumulation of osmolytes such as proline is considered to participate in the osmotic adjustment of plant cells to salinity.

Mutations in the hyperosmotic stress-responsive mitochondrial BASIC AMINO ACID CARRIER2 enhance proline accumulation in Arabidopsis.

Mitochondrial carrier family proteins are diverse in their substrate specificity, organellar location, and gene expression. In Arabidopsis (Arabidopsis thaliana), 58 genes encode these six-transmembrane-domain proteins. We investigated the biological role of the basic amino acid carrier Basic Amino Acid Carrier2 (BAC2) from Arabidopsis that is structurally and functionally similar to ARG11, a yeast ornithine and arginine carrier, and to Arabidopsis BAC1.