Developmental and environmental concurrent expression of sunflower dry-seed-stored low-molecular-weight heat-shock protein and Lea mRNAs.
We have cloned and sequenced three different cDNAs from sunflower seed-stored mRNA. Sequence similarities and response to heat-shock identified one of the cDNAs as a low-molecular-weight heat-shock protein (lmw-HSP). The other two clones showed significant sequence similarity to the cotton and carrot late-embryogenesis-abundant (Lea) proteins D-113 and Emb-1, respectively. The three cDNAs showed similar expression patterns during zygotic embryo development, as well as in vegetative tissues of 3-day-old seedlings in response to stress. Maximal accumulation of all three mRNAs was detected in dry seeds and during embryo mid-maturation stage, in the absence of exogenous stress. In seedlings, mRNAs accumulated to lower levels in response to osmotic stress and exogenous abscisic acid (ABA) treatments. A differential time course of response to osmotic stress was observed: lmw-HSP mRNA accumulation was induced earlier than that of Lea mRNAs. The coordinate accumulation of Lea and lmw-HSP transcripts during embryo development and in response to stress and ABA suggests the existence of common regulatory elements for Lea and lmw-HSP genes, and supports the notion that HSPs might have alternative functions in the plant cell.
Almoguera
C
C
Instituto de Recursos Naturales y Agrobiología, C.S.I.C., Sevilla, Spain.
Jordano
J
J
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics*; D006368:Helianthus / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D012639:Seeds / Q000235:genetics*
D006360:Heat-Shock Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; C066246:late embryogenesis abundant protein, plant; D000040:Abscisic Acid