Characterization of the plastids affected by class-ii albino mutations of maize at the morphological and transcript levels

Han, C. D., Derby, R. J., Schnable, P. S., Martienssen, R. A. (1995) Characterization of the plastids affected by class-ii albino mutations of maize at the morphological and transcript levels. Maydica, 40 (1). pp. 13-22. ISSN 0025-6153

Abstract

Class II albino mutations have been defined to be ones that do not affect pigmentation in endosperm but show a very pale yellow ('off-white') color in seedlings (ROBERTSON, 1975). While class I albinos with white-endosperm and white-seedlings have been extensively studied with respect to carotenoid biosynthesis, little study has been done on class II albino mutants. To obtain molecular insights into the possible roles of the class II nuclear genes in plastid biogenesis during leaf development: we screened and characterized new class II albino mutants derived from transposon Mu and Ac lines. Based on Northern analysis with 61 class II albinos, are selected 14 mutants that had the most substantial alterations in levels and sizes of plastid transcripts. The 14 mutants had almost identical plastid transcript patterns to those of w1 (white 1), a know class II albino, but were distinctly different from those of ho (lemon white), a class I albino. By using electron microscopy, we examined the morphology of plastids affected by three of the class II mutable albinos. The plastids of the mutant tissues were devoid of most of the internal membranes. The most prominent internal structures found in the affected plastids were either vesicle-like membranes or a few lamellae of various sizes. The lamellae were either in parallel groups or scattered. The plastids of older cells contained less lamellar structures than those of younger cells. The plastid morphologies of the class II mutants were different from that of w3 (white 3), a class I albino, grown under the same conditions. All the plastids in revertant cells showed completely normal membrane structures while adjacent mutant cells contained typical mutant plastids. This observation indicates that the genes responsible for class II albinism act on plastid development in a cell-autonomous fashion. Our study shows that a subset of the class II albino mutants impair the expression of plastid genomes and the development of plastids in a unique and distinct way. New mutable class II albinos reported here may provide molecular access to the nuclear genes which play significant roles in plastid biogenesis during leaf development.

Item Type: Paper
Additional Information: Maydica
Uncontrolled Keywords: maize albino mutants plastids morphology transcripts chloroplast gene-expression mutants nuclear plants
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > transcription
bioinformatics > genomics and proteomics > genetics & nucleic acid processing
organism description > plant > maize
organism description > plant
CSHL Authors:
Communities: CSHL labs > Martienssen lab
Depositing User: Matt Covey
Date: 1995
Date Deposited: 13 Dec 2013 16:47
Last Modified: 13 Dec 2013 16:47
URI: https://repository.cshl.edu/id/eprint/28977

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