Abstract
KNOX genes are important regulators for the shoot apical meristem (SAM) formation/maintenance, and their SAM-specific expression is essential for shoot development. Because KNOX genes play a role in maintaining an indeterminate cell state, their ectopic expression in leaves causes abnormal leaf development. Although some regulators of the KNOX expression have been identified so far, it is still unclear how SAM-specific expression of KNOX genes is regulated.
To elucidate a regulatory system, we screened a rice Tos17 mutant panel, and identified 11 recessive mutant lines misexpressing four KNOX genes, OSH1, OSH6, OSH15, OSH71 in their leaves. These lines showed similar phenotype including conical shaped shoot with bladeless leaves, severe dwarfism, and seedling lethality. During leaf development, clear cell formation of mid veins and vacuolation were delayed in these mutant lines.
