Analysis of a stay green mutant, nyc1, in rice.

Abstract

nyc1 was isolated in rice as the recessive mutation that inhibited chlorophyll breakdown during senescence. Such a mutant is called 'stay green' mutant. In nyc1, the inhibition of Chlb breakdown was prominent but Chla breakdown was also inhibited to some extent. Consequently, the Chla/b ratio became nearly 1 at the very late stage of senescence. In nyc1, Rubisco large subunit and Chla binding proteins were degraded but LHCII remained stable even at the very late stage of senescence. HPLC analysis revealed that the degradation of not only Chla and Chlb but also carotenoids that bind LHCII tightly was inhibited in nyc1. These data collectively suggest that nyc1 is the mutant involved in LHCII stability during senescence.