Table 1.

Some genes whose expression levels affect organelle extensions and tubular organelles in Arabidopsis thaliana

Gene	Altered expression level due to	Organelle with major change in morphology	Suggested mechanism	References
ARC3, ARC6, ARC5	Lower expression in mutants	Greatly increased stromules from enlarged chloroplasts	Incomplete chloroplast division apparatus	Pyke (1999); Holzinger et al. (2008)
ATG5	Mutant. Lower expression	Increased stromule abundance and length during starvation conditions	Autophagosome pathway disrupted; causes stress/loss of membrane sequestration	Ishida et al. (2008)
BIGYIN 1	Mutant	Enlarged mitochondria	Component of the mitochondrial division apparatus, a FIS1 homolog	Logan (2006a); Zhang and Hu (2008)
CHUP1	Overexpression	Ectopic protrusions some of which are stromules	OEM localization. Altered protein:lipid ratio	Oikawa et al. (2008)
DRP3A and DRP3B	Mutants	Abnormally longated mitochondria and peroxisomes	Components of mitochondrial and peroxisomal fission machinery	Arimura et al. (2004); Logan et al. (2004); Mano et al. (2004); Fujimoto et al. (2009)
DRP5B (ARC5)	Mutation	Clustered peroxisomes showing membrane constriction but impaired division	Involved in the peroxisome and chloroplast division apparatus	Zhang and Hu (2010)
FIS1A, FIS1B	FIS1A mutation combined with FIS1B RNAi	Enlarged peroxisomes and mitochondria	Required for peroxisome and mitochondrial division apparatus	Zhang and Hu (2008; 2009)
LACS9	Transient overexpression	Ectopic chloroplast extensions	Plastidial acyl coenzyme A synthetase involved in processing of fatty acids produced by chloroplasts	Schnurr et al. (2002); Breuers et al. (2012)
MSL2, MSL3	Double mutant	Enlarged spherical plastids without stromules but the extensions appear upon plant dehydration.	Osmoregulatory mechanism involving plastid mechanosensitive ion channels	Veley et al. (2012)
NMT1/ELM1	Mutant	Elongated mitochondria with strong dilated regions	Required for localization of a fission associated dynamin-related protein to the mitochondrial division site	Logan (2006a); Arimura et al. (2008)
OEP7	Overexpression	Ectopic chloroplast extensions	OEM localized. Altered protein:lipid ratio	Lee et al. (2001)
PARC6	Mutant	Epidermal plastids abnormally elongated and clustered	Impaired division apparatus	Ishikawa et al. (2020)
PEX11C, PEX11D	Overexpression	Elongated peroxisomes	Peroxisome membrane proteins that promote elongation	Lingard and Trelease (2006); Orth et al. (2007)
PEX3-1 PEX3-2i	Double knockdown RNAi	Elongated peroxisomes	Required to maintain the structure of the peroxisome.	Nito et al. (2007)
PGM1	Mutant	Elongated chloroplasts with loose grana. Tubular form more apparent during growth under short day conditions.	Defective in sugar—starch metabolism. Accumulate sucrose during diurnal cycle.	Caspar et al. (1985); Schattat et al. (2012a)
AtTOC64	Transient overexpression	Ectopic protrusions from chloroplasts	OEM localized protein. Altered protein:lipid ratio	Breuers et al. (2012)