THE TM5 MADS BOX GENE MEDIATES ORGAN DIFFERENTIATION IN THE 3 INNER WHORLS OF TOMATO FLOWERS

Citation
L. Pnueli et al., THE TM5 MADS BOX GENE MEDIATES ORGAN DIFFERENTIATION IN THE 3 INNER WHORLS OF TOMATO FLOWERS, The Plant cell, 6(2), 1994, pp. 175-186
Citations number
36
Categorie Soggetti
Biology,"Plant Sciences
Journal title
ISSN journal
10404651
Volume
6
Issue
2
Year of publication
1994
Pages
175 - 186
Database
ISI
SICI code
1040-4651(1994)6:2<175:TTMBGM>2.0.ZU;2-O
Abstract
The tomato MADS box gene no. 5 (TM5) is shown here to be expressed in meristematic domains fated to form the three inner whorls-petals, stam ens, and gynoecia-of the tomato flower. TM5 is also expressed during o rganogenesis and in the respective mature organs of these three whorls . This is unlike the major organ identity genes of the MADS box family from Antirrhinum and Arabidopsis, which function in overlapping primo rdial territories consisting of only two floral whorls each. The devel opmental relevance of the unique expression pattern of this putative h omeotic gene was examined in transgenic plants. In agreement with the expression patterns, antisense RNA of the TM5 gene conferred both earl y and late alterations of morphogenetic markers. Early defects consist of additional whorls or of a wrong number of organs per whorl. Late, organ-specific changes include evergreen, cauline, and unabscised peta ls; green, dialytic, and sterile anthers; and sterile carpels and defe ctive styles on which glandular trichomes characteristic of sepals and petals are ectopically formed. However, a complete homeotic transform ation of either organ was not observed. The early and late floral phen otypes of TM5 antisense plants suggest that TM5 mediates two unrelated secondary regulatory systems. One system is the early function of the floral meristem identity genes, and the other system is the function of the major floral organ identity genes.