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The presence of a specific binding site for a hepta-beta-glucoside elicitor of phytoalexin accumulation has been demonstrated in soybean microsomal membranes. A tyramine conjugate of the elicitor-active hepta-beta-glucoside was prepared and radiolabeled with 125I. The labeled hepta-beta-glucoside-tyramine conjugate was used as a ligand in binding assays with a total membrane fraction prepared from soybean roots. Binding of the radiolabeled hepta-beta-glucoside elicitor was saturable, reversible,

The abilities of a family of chemically synthesized oligo-beta-glucosides, ranging in size from hexamer to decamer, to induce phytoalexin accumulation in soybean cotyledons were investigated to determine which structural elements of the oligoglucosides are important for their biological activity. The results of the biological assays established that the following structural motif is necessary for the oligo-beta-glucosides to have high elicitor activity: [formula; see text] The branched trisaccha

The plant hormone abscisic acid (ABA) triggers cellular tolerance responses to osmotic stress caused by drought and salinity. ABA controls the turgor pressure of guard cells in the plant epidermis, leading to stomatal closure to minimize water loss. However, stomatal apertures open to uptake CO₂ for photosynthesis even under stress conditions. ABA modulates its signaling pathway via negative feedback regulation to maintain plant homeostasis. In the nuclei of guard cells, the clade A t

Plants respond to drought stress by producing abscisic acid, a chemical messenger that regulates gene expression and thereby expedites various physiological and cellular processes including the stomatal operation to mitigate stress and promote tolerance. To trigger or suppress gene transcription under drought stress conditions, the surrounding chromatin architecture must be converted between a repressive and active state by epigenetic remodeling, which is achieved by the dynamic interplay among

Plants remember what they have experienced and are thereby able to confront repeated stresses more promptly and strongly. A subset of the drought responsive genes, called stress memory genes, displayed greatly elevated levels under recurrent drought conditions. To screen for a set of drought stress memory genes in soybean (<i>Glycine max</i> L.), we designed a 180K DNA chip comprising 60-bp probes synthesized <i>in situ</i> to examine 55,589 loci. Through microarray analysis using the DNA chip,

Drought stress memory in plant can alter their physiological, biochemical and molecular to a subsequent stress. An experiment was conducted to determine biochemical parameters of soybean seedlings under drought stress memory. 14-days-old soybean seedlings were subjected to three consecutive water deficit phases (D1, D2, D3), each phase recovered by re-watering (R1, R2, R3), and control plant watering daily (R0). Leave of seedlings from these phases were collected and analyzed. Significantly incr

Jong-Joo Cheong, Winnie Birberg, , , Per J. Garegg, Namgi Hong, Tomoya Ogawa, Michael G. Hahn, Structure-Activity Relationships of Oligo-β-Glucoside Elicitors of Phytoalexin Accumulation in Soybean, The Plant Cell, Vol. 3, No. 2 (Feb., 1991), pp. 127-136