Photosynthesis in Arabidopsis thaliana mutants with reduced chloroplast number.
We have used a class of Arabidopsis mutants altered in the accumulation and replication of chloroplasts (arc mutants) to investigate the effect of reduced chloroplast number on the photosynthetic competence of leaves. Each of the arc mutants examined (arc3, arc5, and arc6) accumulate only a few (2-15) large chloroplasts per mesophyll cell. The increased plastid size maintains a constant plastid to mesophyll cell volume, which has been suggested to compensate for the lower chloroplast number. In fact, we find that reduced chloroplast number has an effect on both the composition and structure of the photosynthetic apparatus, and that each arc mutant has an altered photosynthetic capacity, and we conclude that photosynthetic competence is dependent on proper chloroplast division and development.
Ii
Jotham Austin
JA
School of Life Science and Center for the Study of Early Events in Photosynthesis, Arizona State University, P. O. Box 871601, Tempe, AZ 85287-1601, USA.
Webber
Andrew N
AN
D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D034281:Dynamins / Q000235:genetics; D005453:Fluorescence; D005838:Genotype; D008027:Light; D009154:Mutation / Q000235:genetics*; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism / Q000528:radiation effects / Q000648:ultrastructure
C493630:ARC3 protein, Arabidopsis; C502272:ARC6 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002734:Chlorophyll; C473942:ARC5 protein, Arabidopsis; D034281:Dynamins; D010100:Oxygen