Light Induction of Cell Type Differentiation and Cell-Type-Specific Gene Expression in Cotyledons of a C4 Plant, Flaveria trinervia1

AUTOR(ES)

Shu, Guoping

FONTE

American Society of Plant Physiologists

RESUMO

In Flaveria trinervia (Asteraceae) seedlings, light-induced signals are required for differentiation of cotyledon bundle sheath cells and mesophyll cells and for cell-type-specific expression of Rubisco small subunit genes (bundle sheath cell specific) and the genes that encode pyruvate orthophosphate dikinase and phosphoenolpyruvate carboxylase (mesophyll cell specific). Both cell type differentiation and cell-type-specific gene expression were complete by d 7 in light-grown seedlings, but were arrested beyond d 4 in dark-grown seedlings. Our results contrast with those found for another C4 dicot, Amaranthus hypochondriacus, in which light was not required for either process. The differences between the two C4 dicot species in cotyledon cell differentiation may arise from differences in embryonic and post-embryonic cotyledon development. Our results illustrate that a common C4 photosynthetic mechanism can be established through different developmental pathways in different species, and provide evidence for independent evolutionary origins of C4 photosynthetic mechanisms within dicotyledonous plants.

Documentos Relacionados

• cis-Regulatory Elements for Mesophyll-Specific Gene Expression in the C4 Plant Flaveria trinervia, the Promoter of the C4 Phosphoenolpyruvate Carboxylase GeneW⃞
• Cell-Type-Specific Expression of Plant Cytochrome c mRNA in Developing Flowers and Roots1
• Mutations in the DET1 gene affect cell-type-specific expression of light-regulated genes and chloroplast development in Arabidopsis
• The Influence of Leaf Age on C4 Photosynthesis and the Accumulation of Inorganic Carbon in Flaveria trinervia, a C4 Dicot 1
• Tissue-specific light-regulated expression directed by the promoter of a C4 gene, maize pyruvate,orthophosphate dikinase, in a C3 plant, rice.