Endogenous Nod-Factor-Like Signal Molecules Promote Early Somatic Embryo Development in Norway Spruce1
AUTOR(ES)
Dyachok, Julia V.
FONTE
American Society of Plant Physiologists
RESUMO
Embryogenic cultures of Norway spruce (Picea abies) are composed of pro-embryogenic masses (PEMs) and somatic embryos of various developmental stages. Auxin is important for PEM formation and proliferation. In this report we show that depletion of auxin blocks PEM development and causes large-scale cell death. Extracts of the media conditioned by embryogenic cultures stimulate development of PEM aggregates in auxin-deficient cultures. Partial characterization of the conditioning factor shows that it is a lipophilic, low-molecular-weight molecule, which is sensitive to chitinase and contains GlcNAc residues. On the basis of this information, we propose that the factor is a lipophilic chitin oligosaccharide (LCO). The amount of LCO correlates to the developmental stages of PEMs and embryos, with the highest level in the media conditioned by developmentally blocked cultures. LCO is not present in nonembryogenic cultures. Cell death, induced by withdrawal of auxin, is suppressed by extra supply of endogenous LCO or Nod factor from Rhizobium sp. NGR234. The effect can be mimicked by a chitotetraose or chitinase from Streptomyces griseus. Taken together, our data suggest that endogenous LCO acts as a signal molecule stimulating PEM and early embryo development in Norway spruce.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=148915Documentos Relacionados
- Induced Resistance to Pathogenic Fungi in Norway Spruce1
- Induction of Volatile Terpene Biosynthesis and Diurnal Emission by Methyl Jasmonate in Foliage of Norway Spruce1
- Turgor Regulation via Cell Wall Adjustment in White Spruce1
- Insect Attack and Wounding Induce Traumatic Resin Duct Development and Gene Expression of (—)-Pinene Synthase in Sitka Spruce1
- Early Embryo Development in Fucus distichus Is Auxin Sensitive1