The Effect of Water Stress on the Germination and Nitrate Reductase Activity in Imbibing Agrostemma githago Seeds

Köhler, Karl-Hermann; Schmerder, B.; Sheikhany, H.

doi:10.1016/s0176-1617(11)80364-0

Cited by 9 publications

(1 citation statement)

References 15 publications

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“…Seeds were imbibed in water, 10 μ m ABA (Wang et al . 1996) or 0.5 m mannitol (Kohler et al . 1992) and grown on moist filter papers in Petri plates.…”

Section: Methodsmentioning

confidence: 99%

Expression of Brassica juncea 3‐hydroxy‐3‐methylglutaryl CoA synthase is developmentally regulated and stress‐responsive

2000

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Summary 3-Hydroxy-3-methylglutaryl-coenzyme A synthase (HMGS) is an enzyme in mevalonate biosynthesis. In plants, investigations have focused on HMG CoA reductase (HMGR) and less is known of the preceding enzyme, HMGS. To understand the regulation of HMGS, we have isolated a Brassica juncea cDNA encoding HMGS, BjHMGS1, for use as a hybridization probe in Northern blot analyses. BjHMGS is expressed in all plant organs and shows developmental regulation in¯ower, seed and seedling, with highest expression in early development. In seedlings, expression is highest in young hypocotyls and is induced during the greening of etiolated cotyledons. BjHMGS is down-regulated by abscisic acid, osmotic stress and dehydration, the effects of which arrested seedling growth. Thus BjHMGS expression shows correlation with rapid cell division and growth, like HMGR. This is not unexpected, as mevalonate is the precursor to many essential isoprenoid compounds, including sterols for membrane biogenesis. Wounding, methyl jasmonate or salicylic acid induce BjHMGS expression, suggesting that, like HMGR, HMGS is involved in defence. As in animals, coordinated regulation of HMGS with HMGR occurred in B. juncea upon germination and in response to salicylic acid. HMGS assays con®rmed that Escherichia coliexpressed recombinant BjHMGS1 shows HMGS activity that is inhibited by F244, a speci®c inhibitor of HMGS. Southern blot analysis revealed gene families encoding HMGS in Brassica species and a summation of homologous genes in the fusion amphidiploid genome of B. juncea, a bi-parental species derived from diploids B. nigra and B. campestris.

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“…Seeds were imbibed in water, 10 μ m ABA (Wang et al . 1996) or 0.5 m mannitol (Kohler et al . 1992) and grown on moist filter papers in Petri plates.…”

Section: Methodsmentioning

confidence: 99%