Reduced inositol content and altered morphology in transgenic potato plants inhibited for 1D-myo-inositol 3-phosphate synthase

Citation
R. Keller et al., Reduced inositol content and altered morphology in transgenic potato plants inhibited for 1D-myo-inositol 3-phosphate synthase, PLANT J, 16(4), 1998, pp. 403-410
Citations number
31
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT JOURNAL
ISSN journal
09607412 → ACNP
Volume
16
Issue
4
Year of publication
1998
Pages
403 - 410
Database
ISI
SICI code
0960-7412(199811)16:4<403:RICAAM>2.0.ZU;2-E
Abstract
Myo-inositol is a precursor of many plant metabolites, including polyols, c ell wall components and phosphoinositides. The first committed step in the de novo myo-inositol synthetic pathway is catalysed by the enzyme 1D-myo-in ositol 3-phosphate synthase (MIPS; EC 5.5.1.4), which converts D-glucose 6- phosphate to 1D-myo-inositol 3-phosphate. Suppression of MIPS activity by a n antisense RNA approach in transgenic potato (Solanum tuberosum L.) plants to below 20% of the wild-type level in leaves resulted in strongly reduced levels of inositol, galactinol and raffinose (approximately 7%, 5% and 12% , respectively, of wild-type values). In contrast, increases were observed for concentrations of hexose phosphates (up to 1.7-fold), sucrose (twofold) and starch (two- to fourfold). Transgenic plants exhibited reduced apical dominance, altered leaf morphology, precocious leaf senescence and a decrea se in overall tuber yield. These observations indicate a crucial role for m yo-inositol in plant physiology and development.