Mutation of SlARC6 leads to tissue-specific defects in chloroplast development in tomato

Abstract

The proliferation and development of chloroplasts are important for maintaining the normal chloroplast population in plant tissues. Most studies have focused on chloroplast maintenance in leaves. In this study, we identified a spontaneous mutation in a tomato mutant named suffulta (su), in which the stems appeared albinic while the leaves remained normal. Map-based cloning showed that Su encodes a DnaJ heat shock protein that is a homolog of the Arabidopsis gene AtARC6, which is involved in chloroplast division. Knockdown and knockout of SlARC6 in wild-type tomato inhibit chloroplast division, indicating the conserved function of SlARC6. In su mutants, most mesophyll cells contain only one or two giant chloroplasts, while no chloroplasts are visible in 60% of stem cells, resulting in the albinic phenotype. Compared with mature tissues, the meristem of su mutants suggested that chloroplasts could partially divide in meristematic cells, suggesting the existence of an alternative mechanism in those dividing cells. Interestingly, the adaxial petiole cells of su mutants contain more chloroplasts than the abaxial cells. In addition, prolonged lighting can partially rescue the albinic phenotypes in su mutants, implying that light may promote SlACR6-independent chloroplast development. Our results verify the role of SlACR6 in chloroplast division in tomato and uncover the tissue-specific regulation of chloroplast development.

The DnaJ domain‐containing heat‐shock protein NAL11 determines plant architecture by mediating gibberellin homeostasis in rice (Oryza sativa)

“…NAL11 may be involved in chloroplast development and extensively modulate GA homeostasis NARROW LEAF 11 is an HSP with a DnaJ domain (J protein) from the family the molecular chaperones widely present in plants (Georgopoulos et al, 1979;Waters, 2013). The reported J proteins are primarily localized in chloroplasts and affect chloroplast development, photosynthesis, protein transport, and other processes (Vitha et al, 2003;Chen et al, 2010;Chang et al, 2021). The chloroplast is also the major organelle in which NAL11 is mainly localized (Fig.…”

Integrating physiology, genetics, and transcriptome to decipher a new thermo-sensitive and light-sensitive virescent leaf gene mutant in cucumber

“…Frontiers in Plant Science 13 frontiersin.org 2022), (Schultes et 1996), tomato (Solanum lycopersicon; Chang et al, 2021), and wheat (Triticum aestivum; Li et al, 2013).…”

“…Normally, chloroplasts are found in plants, algae, and protozoa. However, leaf color mutations are associated with chloroplast structural variations in several plants, including rice ( Chen et al, 2018 ), Arabidopsis ( Song et al, 2004 ), tobacco ( Bae et al, 2001 ), pepper ( Capsicum annuum ; Shi et al, 2022 ), maize ( Schultes et al, 1996 ), tomato ( Solanum lycopersicon ; Chang et al, 2021 ), and wheat ( Triticum aestivum ; Li et al, 2013 ). In this study, the chlorophyll a, chlorophyll b, and carotenoid contents of the mutants were significantly reduced, but the pigment composition was consistent with that of the WT.…”

Fine Mapping and Candidate Gene Analysis of BnC08.cds, a Recessive Gene Responsible for Sepal-Specific Chlorophyll-Deficiency in Brassica napus L.

“…These kinds of PPRs involved in chloroplast development have been found in other species, including DG1 ( Chi et al, 2008 ) and YS1 ( Zhou et al, 2010 ) in Arabidopsis , and PPR4 ( Schmitz-Linneweber et al, 2006 ) and PPR10 ( Prikryl et al, 2011 ) in maize. As a tissue-specific albino, a tomato mutant suffulta (su) with albinic stems and visually normal leaves were collected ( Chang et al, 2021 ). Map-based cloning showed that Su encodes a DnaJ heat shock protein, and the homolog gene AtARC6 (accumulation and replication of chloroplasts) in Arabidopsis is involved in chloroplast division.…”

“…A two-step mutation process in the double White Stem 1 homologs has driven the evolution of burley tobacco (Wu et al, 2020). A similar phenotype was identified from a tomato mutant with albinic stems and this is caused by a mutation of SlARC6, which leads to the tissue-specific defects in chloroplast development (Chang et al, 2021).…”