Gene Expression in Response to Abscisic Acid and Osmotic Stress

Seed dormancy and germination

“…Despite the strong desiccation tolerance of many seeds, storage also under dry conditions ultimately leads to a loss of viability. It has been suggested that compounds such as certain sugars and proteins, such as LEA (Late embryogenesis abundant) (Skriver and Mundy, 1990) and Heat shock proteins (Hsps) (Wehmeyer and Vierling, 2000; Hong and Vierling, 2001), that accumulate during the later stages of seed development, have a desiccation protective role. However, mutants like abi5, which show a strong reduction in some LEA proteins (Finkelstein and Lynch, 2000) do not have obvious defects in seed storability.…”

Promoter and expression studies on an Arabidopsis thaliana dehydrin gene

“…In plants exposed to stresses such as low temperature (cold), salt stress or desiccation, a large set of genes is transcriptionally activated [1]. Although no direct evidence is yet available, it is thought that the stress-induced proteins are involved in tolerance [2].…”

“…The phytohormone abscisic acid (ABA) is implicated in the control of processes resulting in tolerance [1,3 5]. Endogenous ABA concentrations increase in plants in response to stress [6] and many, but not all stress-induced genes, are responsive to exogenous ABA treatment [1,[3][4][5]. Many genes that respond to ABA are also expressed during seed development during the late stages of embryogenesis and are thought to be involved in the development of desiccation tolerance [1].…”

Molecular aspects of somatic-to-embryogenic transition in plants

“…The SE system described by Mordhorst et al [124] was used to follow the expression of SERKI in Arabidopsis during the initiation of an embryogenic culture in an altered meristem programl (ampl) mutant background. In response to the presence of 2,4-D in the induction medium, SERKI expression increased in the SAM and the vascular bundles [62,124,151,173,184]. Embryogenic structures originating from the SAM area showed SERKI expression.…”

“…In addition, SERK was detected during flower development and was highest 10 days after pollination [173]. Homologs of SERK have been discovered in several plant species, which includes Dactylis glomerata [184], Zea mays [5], Medicago truncatula [130], Helianthus annuus [198], Oryza sativa [79], Citrus unshiu [178], Theobroma cacao [169,170], and Solanum tuberosum [177]. Analysis of the sequenced Arabidopsis genome revealed that a family of five homologs of the carrot SERK was present.…”