ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Differential expression of two beta-D-xylosidase genes during fruit development and ripening in tomato

A. Itai , K. Ishihara , K. Tanabe, F. Tamura and J.D. Bewley

Proceedings of 26th International Horticultural Congress. Volume of Abstract . Toronto, Canada, 11-17 August, 2002. Abstract S09-P-165. pp. 262-263.

2002

บทคัดย่อ

The plant cell wall is modified during almost all plant developmental processes such as seed germination, fruti development, fruit ripening and abscission. Modifications to the cell wall are thought to be mediated by cell wass hydrolases, including a beta-D-xylosidase that participates in the breakdown of xylan. We have cloned two beta-D-xylosidase genes, designated LeXYL1 and LeXYL2, expressed in tomato fruit. The deduced amino acid sequence of LeXYL1 shows 74% identity with that of LeXYL2. Accumulation of mRNA for the two beta-D-xylosidases was examined during fruit development and ripening. LeXYL2 mRNA was relatively highly expressed during early fruit development and decreased gradually after the onset of ripening. In contrat, LeXYL1 mRNA was not present during fruit development, but was present later during ripening. LeXYL1 and LeXY2 each showed diverse patterns of expression during fruit development and ripening. We studied the transcription of LeXYL1 and LeXY2 in wild type (‘Alisa Craig’) fruit and ripening-impaired mutants, Nr2, nor, and rin. In the ripe fruit of the mutants, there was no expression of LeXYL1, whereas mRNA abundance of LeXYL2 was similar to that in mature-green wild-type fruit. These two betaa-D-xylosidase genes are subject to distinct regulatory control during fruit development and ripening. These results suggest that the product of the LeXYL1 gene is responsible for ripening-associated cell wall changes.