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Characterization of chloroplast division using the Arabidopsis mutant arc5

Version 2 2024-06-03, 00:30
Version 1 2023-11-02, 04:55
journal contribution
posted on 2024-06-03, 00:30 authored by EJ Robertson, SM Rutherford, RM Leech
Abstract arc5 is a chloroplast division mutant of Arabidopsis thaliana. To identify the role of ARC5 in the chloroplast replication process we have followed the changes in arc5 chloroplasts during their perturbed division. ARC5 does not affect proplastid division but functions at a later stage in chloroplast development. Chloroplasts in developing mesophyll cells of arc5 leaves do not increase in number and all of the chloroplasts in mature leaf cells show a central constriction. Young arc5 chloroplasts are capable of initiating the division process but fail to complete daughter-plastid separation. Wild-type plastids increase in number to a mean of 121 after completing the division process, but in the mutant arc5 the approximately 13 plastids per cell are still centrally constricted but much enlarged. As the arc5 chloroplasts expand and elongate without dividing, the internal thylakoid membrane structure becomes flexed into an undulating ribbon. We conclude that the ARC5 gene is necessary for the completion of the last stage of chloroplast division when the narrow isthmus breaks, causing the separation of the daughter plastids.

History

Journal

PLANT PHYSIOLOGY

Volume

112

Pagination

149-159

Location

United States

ISSN

0032-0889

eISSN

1532-2548

Language

English

Issue

1

Publisher

AMER SOC PLANT PHYSIOLOGISTS