Changes in late-embryogenesis-abundant (LEA) messenger RNAs and dehydrins during maturation and premature drying ofRicinus communis L. seeds

• Published in: Planta Vol. 201; no. 1; pp. 27 - 35
• Main Authors: Han, Bin, Wayne Hughes, D., Galau, Glenn A., Derek Bewley, J., Kermode, Allison R.
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.03.1997
• Subjects: Desiccation; Drying; Embryonic growth stage; Proteins; Seeds
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/BF01258677

InRicinus communis L. (castor bean) endosperms, two classes of Late Embryogenesis Abundant (Lea) transcripts were first detected during mid-development (at 30-35 days after pollination, DAP) and peaked at 50 DAP, just prior to the onset of desiccation. Most of the Class 1 mRNAs declined substantially during desiccation itself; Class 11 mRNAs remained abundant in the mature dry (60 DAP) seed. Following imbibition, allLea mRNAs abundant in the mature dry seed declined rapidly (within 5-24 h). Premature drying of developing 35-DAP seeds resulted in the loss of storage-protein mRNAs (Leg B Mat I); following rehydration, mRNAs encoding post-germinative proteins (Germ D91, D30 and D38) increased in the endosperm. TheLea mRNAs present in the developing fresh seed at 35 DAP were preserved, but did not increase in response to premature desiccation; upon rehydration theseLea mRNAs declined within 5 h. During seed development, substantial changes occurred in the synthesis of a subset of LEA proteins referred to as 'dehydrins'; in particular, new dehydrin polypeptides were induced between 40 and 60 DAP. Such proteins were not as evident in prematurely dried endosperms. In contrast to the rapid loss ofLea mRNAs during germination, many of the dehydrin proteins abundant in the dried seed persisted following imbibition or rehydration.[PUBLICATION ABSTRACT]