Molecular marker-based characterization in candidate plus trees of Pongamia pinnata, a potential biodiesel legume

Molecular marker studies provide valid guidelines for collection, characterization and selective cultivation of elite Pongamia germplasm that can be exploited further for its improvement through breeding and marker assisted selection for improved characters and oil yield towards biodiesel production

Rhizobium pongamiae sp. nov. from Root Nodules of Pongamia pinnata

Pongamia pinnata has an added advantage of N2-fixing ability and tolerance to stress conditions as compared with other biodiesel crops. It harbours “rhizobia” as an endophytic bacterial community on its root nodules. A gram-negative, nonmotile, fast-growing, rod-shaped, bacterial strain VKLR-01T was isolated from root nodules of Pongamia that grew optimal at 28°C, pH 7.0 in presence of 2% NaCl. Isolate VKLR-01 exhibits higher tolerance to the prevailing adverse conditions, for example, salt stress, elevated temperatures and alkalinity. Strain VKLR-01T has the major cellular fatty acid as C18:1  ω7c (65.92%). Strain VKLR-01T was found to be a nitrogen fixer using the acetylene reduction assay and PCR detection of a nifH gene. On the basis of phenotypic, phylogenetic distinctiveness and molecular data (16S rRNA, recA, and atpD gene sequences, G + C content, DNA-DNA hybridization etc.), strain VKLR-01T = (MTCC 10513T = MSCL 1015T) is considered to represent a novel species of the genus Rhizobium for which the name Rhizobium pongamiae sp. nov. is proposed. Rhizobium pongamiae may possess specific traits that can be transferred to other rhizobia through biotechnological tools and can be directly used as inoculants for reclamation of wasteland; hence, they are very important from both economic and environmental prospects

Metabolite profiling and expression analysis of flavonoid, Vitamin C and tocopherol biosynthesis genes in the antioxidant-rich sea buckthorn (Hippophae rhamnoides L.)

In this study, phenolic compounds were analyzed in developing berries of four Canadian grown sea buckthorn (Hippophae rhamnoides L.) cultivars ('RC-4', 'E6590', 'Chuyskaya' and 'Golden Rain') and in leaves of two of these cultivars. Among phenolic acids, p-coumaric acid was the highest in berries, while gallic acid was predominant in leaves. In the flavonoid class of compounds, myricetin/rutin, kaempferol, quercetin and isorhamnetin were detected in berries and leaves. Berries of the 'RC-4' cultivar had approximately ≥2-fold higher levels of myricetin and quercetin at 17.5 mg and 17.2 mg/100 g FW, respectively, than the other cultivars. The flavonoid content in leaves was considerably more than in berries with rutin and quercetin levels up to 135 mg and 105 mg/100 g FW, respectively. Orthologs of 15 flavonoid biosynthesis pathway genes were identified within the transcriptome of sea buckthorn mature seeds. Semi-quantitative RT-PCR analysis of these genes in developing berries indicated relatively higher expression of genes such as CHS, F3′H, DFR and LDOX in the 'RC-4' cultivar than in the 'Chuyskaya' cultivar. Vitamin C levels in ripened berries of the Canadian cultivars were on the high end of the concentration range reported for most other sea buckthorn cultivars. Orthologs of genes involved in vitamins C and E biosynthesis were also identified, expanding the genomic resources for this nutritionally important plant