Morphological,cytological and molecular marker analyses of ‘Tapestry’ caladium variants reveal diverse genetic changes and enable association of leaf coloration pattern loci with molecular markers

Plant Cell, Tissue and Organ Culture (PCTOC) - Somaclonal variation and induced mutation are highly valuable sources of genetic variation for genetic improvement and research in horticultural...     

Characterization of freezing tolerance and vernalization in Vern-, a spring-type Brassica napus line derived from a winter cross

Exposure of winter brassicas to periods of low temperature decreases the transition required from vegetative to reproductive growth. This low-temperature exposure also results in the acquisition of freezing tolerance. To investigate the relationship between vernalization and freezing tolerance, homozygous microspore-derived (DH) lines were developed from reciprocal crosses between two winter cultivars of Brassica napus L., cv. Cascade and cv. Rebel. A resulting line, termed Vern-, expressed a high degree of freezing tolerance and was selected for study. Analysis of growth and development revealed that Vern- is a true spring type, having completely lost the vernalization requirement. Using markers previously mapped in B. rapa, it was concluded that Vern- inherited freezing-tolerance alleles from Cascade. With regard to vernalization and flowering time, Rebel, although traditionally classified as a winter type, carries spring alleles at the major and some of the minor loci. Vern- inherited these alleles from Rebel, in addition to one spring allele from Cascade. Thus, spring alleles from both parents were critical in establishing the spring phenotype observed in Vern-.     

Comparative Proteomics of Chromium-Transformed Beas-2B Cells by 2D-DIGE and MALDI-TOF/TOF MS

Continuation of prolonged treatment against arsenicosis with conventional chelating therapy is a global challenge. The present study was intended to evaluate the defensive effect of arjunolic acid against arsenic-induced oxidative stress and female reproductive dysfunction. Wistar strain adult female rats were given sodium arsenite (10 mg/kg body weight) in combination with arjunolic acid (10 mg/kg body weight) orally for two estrous cycles. Electrozymographic analysis explored that arjunolic acid co-treatment counteracted As³⁺-induced ROS production in uterine tissue by stimulating the activities of endogenous enzymatic antioxidants. Arjunolic acid was able to enhance the protection against mutagenic uterine DNA breakage, necrosis, and ovarian–uterine tissue damages in arsenicated rats by improving the ovarian steroidogenesis. The mechanisms might be coupled with the augmentation of antioxidant defense system, partly through the elimination of arsenic with the involvement of S-adenosyl methionine pool where circulating levels of vitamin B₁₂, folic acid, and homocysteine play critical roles as evidenced from our present investigation.     

Factors affecting Agrobacterium-mediated transformation and regeneration of sweet orange and citrange

Epicotyl explants of sweet orange and citrange were infected with Agrobacterium strain EHA101 harboring binary vector pGA482GG, and factors affecting the plant regeneration and transformation efficiency were evaluated. Increasing the wounded area of explants by cutting longitudinally into two halves, and optimization of inoculation density, dramatically enhanced both regeneration and transformation frequency. Inclusion of 2,4-dichlorophenoxyacetic acid (2,4-D) in the explant pretreatment medium and the co-culture medium improved the transformation efficiency by decreasing the escape frequency. More than 90% rooting frequency of transformed citrange shoots was achieved by two-step culture: first on media supplemented with auxins, and then on media without hormones. Inclusion of 20 mg l^–1 kanamycin in rooting medium efficiently discriminated transformed shoots from non-transgenic escaped shoots. Shoot grafting in vitro was used to regenerate transformed plants, due to the slow growth of most sweet orange shoots.