A virescent gene V1 determines the expression timing of plastid genes for transcription/translation apparatus during early leaf development in rice
Article first published online: 5 MAR 2002
The Plant Journal
Volume 12, Issue 6, pages 1241–1250, December 1997
How to Cite
Kusumi, K., Mizutani, A., Nishimura, M. and Iba, K. (1997), A virescent gene V1 determines the expression timing of plastid genes for transcription/translation apparatus during early leaf development in rice. The Plant Journal, 12: 1241–1250. doi: 10.1046/j.1365-313x.1997.12061241.x
- Issue published online: 5 MAR 2002
- Article first published online: 5 MAR 2002
- Received 3 April 1997; revised 30 June 1997; accepted 14 July 1997.
- Cited By
Differentiation of proplastids into functionally active chloroplasts is one of the most significant changes in cellular organization associated with leaf development in higher plants. This process involves activation of a large number of nuclear and chloroplast genes. A central question, therefore, concerns the nature and origin of the signals that initiate and control this process. The rice nuclear mutant, virescent-1 (v1), is temperature-conditional and develops chlorotic leaves when grown at restrictive temperatures. We report here the effects of v1 mutation on the expressions of plastid and nuclear genes during leaf development. In the wild-type rice seedlings, the transcripts of the plastid RNA polymerase gene (rpoB) and ribosomal protein genes (rps7, rps15) accumulated during a strictly limited period of early leaf development, prior to the accumulation of the transcripts of photosynthetic genes (rbcL, RbcS, psbA, Lhc). This period coincides very closely with the leaf developmental stage (late P4) at which the V1 gene gives the signal that determines the virescent phenotype. On the contrary, in the v1 seedlings grown at a restrictive temperature (20°C), this stage-specific accumulation of the rpo and rps transcripts was missing. Instead, the accumulation of these transcripts occurred during a later stage of leaf maturation. In such mutant seedlings, the expression of other plastid genes (psbA, rbcL, 16S rDNA) was strongly suppressed and the normal chloroplast development was disturbed. These data indicate that the V1 gene controls the timing of expression of the key plastid genes for the transcription/ translation apparatus that are essential for the subsequent activation of other plastid genes.