These two authors contributed equally to this work.
Effects of arc3, arc5 and arc6 Mutations on Plastid Morphology and Stromule Formation in Green and Nongreen Tissues of Arabidopsis thaliana†
Article first published online: 29 AUG 2008
© 2008 The Authors. Journal Compilation. The American Society of Photobiology
Photochemistry and Photobiology
Volume 84, Issue 6, pages 1324–1335, November/December 2008
How to Cite
Holzinger, A., Kwok, E. Y. and Hanson, M. R. (2008), Effects of arc3, arc5 and arc6 Mutations on Plastid Morphology and Stromule Formation in Green and Nongreen Tissues of Arabidopsis thaliana. Photochemistry and Photobiology, 84: 1324–1335. doi: 10.1111/j.1751-1097.2008.00437.x
This invited paper is part of the Symposium-in-Print: Photosynthesis.
- Issue published online: 3 NOV 2008
- Article first published online: 29 AUG 2008
- Received 21 May 2008, accepted 30 June 2008
Mutations in the ARC3, ARC5 and ARC6 genes of Arabidopsis thaliana affect chloroplast division. We investigated whether ARC3, ARC5 and ARC6 are also involved in determining plastid morphology in nongreen tissues, where stromules, stroma-filled tubular extensions of the plastid envelope membrane, are more abundant than in mesophyll cells. Using plastid-targeted green fluorescent protein to observe plastids throughout the organs of these mutants, we have discovered a number of new mutant phenotypes. The size of arc3 plastids was heterogeneous in various tissues. arc5 plastids appeared wild-type in the majority of nongreen tissues examined. However, in cells of stamen filaments, the arc5 mutant showed an increase in the frequency of stromules. Increased stromule frequency was observed for a number of organs in the arc6 mutant. Some arc6 cells contained heterogeneous mixtures of plastids; epidermal cells of hypocotyls, stamen filaments and the bases of petals possessed both very large chloroplasts as well as much smaller nongreen plastids. Quantitative analysis in hypocotyl cells revealed that the alteration in stromule length in arc3 and arc6 mutants occurred despite wild-type plastid densities. Thus, in hypocotyls, the effects of the arc3 and arc6 mutations on stromule length and frequency are independent of changes in plastid division. Although electron micrographs of stromules emanating from chloroplasts have rarely been reported, within the arc3 mutant, narrow, 40–50 nm diameter, recoiled stromules could be followed for about 10 μm in electron micrographs of leaf tissue.