Editing Plastid (section)

==DNA damage and repair==

The plastid [[DNA]] of [[maize]] seedlings is subjected to increasing damage as the seedlings develop.<ref name="pmid25261192">{{cite journal | vauthors = Kumar RA, Oldenburg DJ, Bendich AJ | title = Changes in DNA damage, molecular integrity, and copy number for plastid DNA and mitochondrial DNA during maize development | journal = Journal of Experimental Botany | volume = 65 | issue = 22 | pages = 6425–39 | date = December 2014 | pmid = 25261192 | pmc = 4246179 | doi = 10.1093/jxb/eru359 }}</ref> The DNA damage is due to oxidative environments created by [[photo-oxidation of polymers|photo-oxidative reactions]] and [[photosynthesis|photosynthetic]]/ [[electron transport chain|respiratory electron transfer]]. Some DNA molecules are [[DNA repair|repaired]] but DNA with unrepaired damage is apparently degraded to non-functional fragments.

[[DNA repair]] proteins are encoded by the cell's [[nuclear genome]] and then translocated to plastids where they maintain [[genome]] stability/ integrity by repairing the plastid's DNA.<ref name="pmid26579143">{{cite journal | vauthors = Oldenburg DJ, Bendich AJ | title = DNA maintenance in plastids and mitochondria of plants | journal = Frontiers in Plant Science | volume = 6 | pages = 883 | date = 2015 | pmid = 26579143 | pmc = 4624840 | doi = 10.3389/fpls.2015.00883 | doi-access = free }}</ref> For example, in [[chloroplast]]s of the moss ''[[Physcomitrella patens]]'', a protein employed in DNA mismatch repair (Msh1) interacts with proteins employed in recombinational repair ([[RecA]] and RecG) to maintain plastid genome stability.<ref name="pmid28407383">{{cite journal | vauthors = Odahara M, Kishita Y, Sekine Y | title = MSH1 maintains organelle genome stability and genetically interacts with RECA and RECG in the moss Physcomitrella patens | journal = The Plant Journal | volume = 91 | issue = 3 | pages = 455–465 | date = August 2017 | pmid = 28407383 | doi = 10.1111/tpj.13573 | doi-access = free }}</ref>