Comparative phenotypic and physiological characteristics of spotted Leaf 6 (spl6) and brown leaf Spot2 (bl2) Lesion Mimic Mutants (LMM) in rice

Abstract

Spontaneous necrotic lesions were found in a lesion mimic mutant brown leaf spot 2 (bl2) without pathogenic infection. Small spots in the seedlings appeared at the four leaves stage and gradually grew into a large round and black area with a gray center on the leaf surfaces. Lower growth habit and lower agronomic trait values with reduced stature, tiller, and panicle number, as well as lower yield potential were noted in the mutants relative to the trait values of the wild-type plants. Microscopic analysis revealed that mesophyll chloroplast was severely damaged or absent in the spotted area of the mutant leaves. Total chlorophyll content, hydrogen peroxide level, and catalase activity were increased at up to 45 days after germination and were dropped at 60 d in the mutant leaves. However, the total protein contents were reduced slightly with a growth period of up to 45 days and were increased at 60 days after germination. A gradual increment of the total ascorbic acid contents in the mutants were observed with advanced plant age, but increased until 45 days and dropped comparatively at 60 days in the wild-type leaves. Increased gene transcriptions of OsPDI and OsGPX1 were noted in the spotted leaves as compared to the non-spotted leaves of the mutant and wild-type leaves, whereas transcripts of OsTPX were transcribed at lower levels in the spotted leaves as compared to the non-spotted leaves. The genetic nature of the bl2 mutant indicated that the F(1) plants evidenced the wild-type phenotype and that bl2 was governed by a single recessive gene.

Studies on the effects of pericarp pigmentation on grain development and yield of black rice

“…Agronomic data were recorded from rice in the vegetative and reproductive stages and during postharvest. Different phenotypic traits of purple pericarp, brown pericarp and white pericarp rice plants were also recorded according to Matin et al (2010).…”

Deterioration of Antioxidant Competence in Barley Lesion Mimic Mutant 194

“…In wheat, the yield components and plant height of the LMMs are similar with those of the mother line [33], indicating that the presence of the lesions mimic phenotype in the mutant did not have a substantial effect on its agronomic performance. However, lower values were obtained for agronomic traits such as stature, tiller number, and panicle number, and a lower yield potential was detected in the rice bl2 LMM compared with the WT [34]. Furthermore, the tiller number and seed-setting rate of the wheat LMM I30 were found not to be significantly different from the WT, but the thousand-seed weight and yield were reduced [35].…”

The DnaJ OsDjA7/8 is essential for chloroplast development in rice (Oryza sativa)

“…The leaves were then prefixed with 3% glutaraldehyde. Subsequently, post-fixed in 1% osmium tetroxide, dehydrated in series acetone, infiltrated in Epox 812 for four hours, and embedded (Matin et al, 2010). The sections were stained with methylene blue and ultrathin sections followed by cutting with diamond knife, staining with uranyl acetate and lead citrate.…”