Variability of Chloroplast DNA of Extranuclear Sunflower Mutants

Abstract

A comparative analysis of full-genome sequences of chloroplast DNA (cpDNA) of the original inbred line 3629 and three extranuclear mutants, which were obtained by the method of mutagenesis induced with N-nitroso-N-methylurea (NMU) and characterized by different level of chlorophyll insufficiency (en:chlorina-7-yellow-green leaves; chlorophyll content (a + b)-67.8% with respect to the line 3629, variegated-10-leaves with white zones; chlorophyll content (a + b)-2.9% with respect to the line 3629 and variegated-13-leaves with yellow zones; chlorophyll content (a + b)-6.1% with respect to the line 3629), has been carried out. Single-parent maternal inheritance of chlorophyll defects was confirmed by analysis of progeny obtained from reciprocal crossbreedings between the original line 3629 and mutants. Chlorophyll mutants carried modified cpDNA unique for each mutant. We anticipate that chlorophyll defect of en:chlorina-7 may control the observed non-synonymous mutations (transitions) in the genes rpoB, psaA and psbB, which encode β-subunit of RNA-polymerase, the A1 apoprotein of chlorophyll a of the photosystem I, P700 and 47 kDa protein of the photosystem II respectively. In variegated-10, it may control mutations in the genes rpoA and rpoC2, which encode α and β" subunits of RNA-polymerase and in variegated-13-two mutations in the ycf3 gene that encodes photosystem I assembly factor.

A State of PSI and PSII Photochemistry of Sunflower Yellow-Green Plastome Mutant

“…Previous studies have revealed non-synonymous mutations in the en: chlorine 7 plastid genes -psaA, psbB (Markin et al, 2016). Hence the chlorophyll deficient phenotype may be associated with an impaired function of core subunits of PSI (psaA) either PSII (psbB) or with the disturbance of both proteins.…”

“…Further investigation by Markin et al (2016) has shown 7 SNP in plastid genome of the en:chlorine-7 line compared to the 3629 line, however only 3 SNP in genes rpoB, psaA, psbB were producing amino acid substitutions (nonsynonymous substitutions). The latter were represented by following substitutions: serine for leucine in 138 position of β-subunit of RNA-polymerase (rpoB), threonine for isoleucine in 528 position of photosystem I P700 chlorophyll a apoprotein A1 (psaA) and histidine for tyrosine in 157 position of photosystem II CP47 reaction center protein (psbB) (Markin et al, 2016).…”

“…Most of such kind researches are carried out on mutants with yellow-green leaf color, so called «chlorina phenotype» (Li et al, 2013;Brestic et al, 2015). Chlorina mutants have been identified in many higher plants, such as Arabidopsis (Harper et al, 2004), rice (Chen et al, 2013), wheat (Li et al, 2013), barley (Preiss and Thornber, 1995), maize (Asakura et al, 2008), tea (Wang et al, 2014), sunflower (Markin et al, 2016) and others. The investigation of genes associated with mutant phenotype is an actual issue for genetics of photosynthesis.…”

The Investigation of Organelle Genomes of Extra Nuclear Sunflower Mutants with Variegated Phenotype

“…The hybridologic analysis was performed under the field conditions similar to past research (Markin et al, 2016). The chlorophyll content in the green and mutant tissues was evaluated by the absorption spectra of 85% acetone extracts of leaves collected at the budding phase (Shlyk, 1971).…”

“…1). Previously, using WGS sequencing, we have investigated the variability of chloroplast DNA (cpDNA) in extra nuclear chlorophyll mutants of sunflower with various types of chlorophyll deficiency (Markin et al, 2016). However, we studied complete chloroplast genome sequences of only two variegated mutant lines (variegated-10 and variegated-13).…”