Expression and Regulation of the Arabidopsis thaliana Cel1 Endo 1,4 beta Glucanase Gene During Compatible Plant-Nematode Interactions.
The root-knot nematode Meloidogyne incognita is an obligate endoparasite of plant roots and stimulates elaborate modifications of selected root vascular cells to form giant cells for feeding. An Arabidopsis thaliana endoglucanase (Atcel1) promoter is activated in giant cells that were formed in Atcel1::UidA transgenic tobacco and Arabidopsis plants. Activity of the full-length Atcel1 promoter was detected in root and shoot elongation zones and in the lateral root primordia. Different 5' and internal deletions of regions of the 1,673 bp Atcel1 promoter were each fused to the UidA reporter gene and transformed in tobacco, and roots of the transformants were inoculated with M. incognita to assay for GUS expression in giant cells and noninfected plant tissues. Comparison of the Atcel1 promoter deletion constructs showed that the region between -1,673 and -1,171 (fragment 1) was essential for Atcel1 promoter activity in giant cells and roots. Fragment 1 alone, however, was not sufficient for Atcel1 expression in giant cells or roots, suggesting that cis-acting elements in fragment 1 may function in consort with other elements within the Atcel1 promoter. Root-knot nematodes and giant cells developed normally within roots of Arabidopsis that expressed a functional antisense construct to Atcel1, suggesting that a functional redundancy in endoglucanase activity may represent another level of regulatory control of cell wall-modifying activity within nematode feeding cells.
Sukno
Serenella
S
Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77845; The Institute of Plant Sciences and Genetics in Agriculture and The Otto Warburg Minerva Center for Agricultural Biotechnology Faculty of Agricultural, Food and Environmental Quality Sciences The Hebrew University of Jerusalem, Rehovot 76100, Israel; Department of Plant Pathology, NC State University, Raleigh, NC 27695- 7616.
Shimerling
Orit
O
McCuiston
Jamie
J
Tsabary
Galit
G
Shani
Ziv
Z
Shoseyov
Oded
O
Davis
Eric L
EL