Abstract: 【Objective】Biosynthesis of chlorophyll comprises a number of challenging topics. Chlorophyll-deficient mutants play an important role in exploring biochemical and molecular aspects of its pathway and regulation. 【Method】Chlorophyll- deficient rice, W1, was analyzed by methods of green gel electrophoresis, SDS-PAGE, Western blotting, Northern blotting and detecting precursors of chlorophyll synthesis.【Result】W1 mutant had a significantly decreased amount of chlorophyll, and so did thylakoid proteins, especially Light-Harvesting-Complex II (LHCII) trimers. Western blotting further revealed that LHCII apoproteins in W1 dropped to 1/3 of its amount in wild type. Northern blotting showed a close transcription ability between W1 and its wild type. The contents of chlorophyll synthesis precursors, from δ-aminolevulinic acid (ALA) to protochlorophyllide (Pchlide), equaled to or were greater than those accumulated in W1. However, its chlorophyllide (Chlide), Chl a and Chl b markedly decreased. 【Conclusion】Analysis has proved that the reason for decreased LHCII level in W1 is not due to the reduced transcription and its mRNA accumulation, a possible inefficient synthesis from Pchlide to Chlide primarily attributed to the lowered chlorophylls in W1.

Key words: Thylakoid membranes, LHCII, Chlorophyll synthesis precursors, Rice (Oryza sativa L.)