Pvlea-18, a Member of a New Late-Embryogenesis-Abundant Protein Family That Accumulates during Water Stress and in the Growing Regions of Well-Irrigated Bean Seedlings¹

José M. Colmenero-Flores, Liz P. Moreno, Claudia E. Smith², and Alejandra A. Covarrubias^*

Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, Cuernavaca, Morelos 62250, México

Pvlea-18 is a novel stress gene whose transcript is present in the dry embryo and the endosperm from bean (Phaseolus vulgaris) seeds. It accumulates in vegetative tissues in response to water deficit and abscisic acid application (J.M. Colmenero-Flores, F. Campos, A. Garciarrubio, A.A. Covarrubias [1997] Plant Mol Biol 35: 393-405). We show that the Pvlea-18 gene encodes a 14-kD protein that accumulates during late embryogenesis. Related proteins have been detected in both monocots and dicots, indicating that PvLEA-18 is a member of a new family of LEA (Late Embryogenesis Abundant) proteins. We also show that the PvLEA-18 transcript and protein accumulate not only in different organs of the bean seedlings during water stress but also in well-irrigated seedlings. This accumulation occurs in seedling regions with more negative values of water and osmotic potentials, such as the growing region of the hypocotyl. This phenomenon has not previously been described for LEA proteins. Immunohistochemical localization showed that the PvLEA-18 protein is present in the nucleus and cytoplasm of all cell types, with a higher accumulation in the epidermis and vascular cylinder tissues, particularly in protoxylem cells and root meristematic tissues. We found a similar localization but a higher abundance in water-stressed seedlings.

Plant Physiol. (1999) 120: 93-104
Copyright Clearance Center:   0032-0889/99/120//12
© 1999 American Society of Plant Physiologists

This article has been cited by other articles:

				M. Battaglia, Y. Olvera-Carrillo, A. Garciarrubio, F. Campos, and A. A. Covarrubias The Enigmatic LEA Proteins and Other Hydrophilins Plant Physiology, September 1, 2008; 148(1): 6 - 24. [Full Text] [PDF]

				K. KIKUCHI, M. KOIZUMI, N. ISHIDA, and H. KANO Water Uptake by Dry Beans Observed by Micro-magnetic Resonance Imaging Ann. Bot., September 1, 2006; 98(3): 545 - 553. [Abstract] [Full Text] [PDF]

				J. Medina, R. Catalá, and J. Salinas Developmental and Stress Regulation of RCI2A and RCI2B, Two Cold-Inducible Genes of Arabidopsis Encoding Highly Conserved Hydrophobic Proteins Plant Physiology, April 1, 2001; 125(4): 1655 - 1666. [Abstract] [Full Text]