Analysis of sequence variability and transcriptional profile of cannabinoid synthase genes in cannabis sativa l. Chemotypes with a focus on cannabichromenic acid synthase

Cannabis sativa L. has been long cultivated for its narcotic potential due to the accumulation of tetrahydrocannabinolic acid (THCA) in female inflorescences, but nowadays its production for fiber, seeds, edible oil and bioactive compounds has spread throughout the world. However, some hemp varieties still accumulate traces of residual THCA close to the 0.20% limit set by European Union, despite the functional gene encoding for THCA synthase (THCAS) is lacking. Even if some hypotheses have been produced, studies are often in disagreement especially on the role of the cannabichromenic acid synthase (CBCAS). In this work a set of European Cannabis genotypes, representative of all chemotypes, were investigated from a chemical and molecular point of view. Highly specific primer pairs were developed to allow an accurate distinction of different cannabinoid synthases genes. In addition to their use as markers to detect the presence of CBCAS at genomic level, they allowed the analysis of transcriptional profiles in hemp or marijuana plants. While the high level of transcription of THCAS and cannabidiolic acid synthase (CBDAS) clearly reflects the chemical phenotype of the plants, the low but stable transcriptional level of CBCAS in all genotypes suggests that these genes are active and might contribute to the final amount of cannabinoids

Kernel weight in maize: genetic control of its physiological and compositional determinants in a dent × flint-caribbean RIL population

The genetic control of maize kernel weight (KW) determination could be studied through its physiological and/ or compositional determinants. Our objective was to dissect the genetic control of maize KW by analyzing its physiological (KGR: kernel growth rate; KFD: kernel filling duration) and compositional (protein, oil, starch) determinants in a dent×flint Caribbean RIL population, which combines a broad genetic background with grains of high added value for industry. An additional objective was to determine the stability of the genetic control under contrasting growing conditions, for which soil nitrogen offer was modified across experiments. Heritability (H2) values were high for KW (H2 = 0.74) and intermediate for the other traits (from 0.62 to 0.42). Kernel weight had a strong correlation with KFD (r = 0.69), KGR (r = 0.60) and protein concentration (r = 0.56). Ten joint QTL with inconsistent effects across years and seven epistatic interactions were detected. Despite changes in effect size, most QTL were significant under both environments. Nine QTL were associated with variations in potential KW (KW ), mean KW, KGR and oil concentration, eight with variations in protein and starch concentration and seven with KFD. Epistatic interactions were related to regions with significant main effects. The most important finding was the existence of a common QTL for KW , KGR and KFD on chromosome 5, for which there was no previous report. Results increased our knowledge on the genetic control of KW through its phenotypic and genetic correlation with KFD, confirming the need to explore different physiological strategies in different genetic backgrounds

Stability of the B-Glucuronidase Gene in a RO Population of Grape (Vitis ruspestris S.)

A study on the stability of the 6-glucuronidase gene has been conducted in a population of transgenic plants regenerated from somatic embryos of Vitis rupestris S. Molecular tests demonstrated no loss of the inserted gene following either the long-term embryo culture and the plant regeneration events. Dot-Blot analysis proved to be a useful assay for a simultaneous assay of the exogenous gene in the population, and Southern Blot analysis showed the marker gene in the inserted form with a agreeable efficiency (92 % )

Effects of gamma-ray treatment on Cannabis sativa pollen viability

The viability and the in vitro germination capability of hemp pollen (cv. Carmagnola) were studied. Viability tests were based on the microscopic observation of the fluorescence of loaded fluorescein diacetate (FDA), while, for germinability tests, five different media were tested. The effects of irradiation with 7-rays on pollen viability and germination and on seed set were also studied, at three different irradiation doses (20, 60 and 100 krad). The results show that in one of the media tested, about 85-90% of the pollen grains are viable and able to germinate in control samples, and that while viability measured by FDA test is not affected by increased 7-ray doses, the pollen in vitro germinability drops to about one-half of the controls at the maximum "y-ray dose employed, 100 krad. Seed set of hemp plants pollinated with the irradiated pollen dropped to less than 1% of that of plants pollinated by untreated pollen for the higher dose used. The different media suitable for in vitro germination of hemp pollen, and the observed lack of correspondence between viability and germination capacity tests are discussed

Oxidation of External NAD(P)H by Mitochondria from Taproots and Tissue Cultures of Sugar Beet (Beta vulgaris).

The present study compares the exogenous NAD(P)H oxidation and the membrane potential ([delta][psi]) generated in mitochondria isolated from different tissues of an important agricultural crop, sugar beet (Beta vulgaris}. We observed that mitochondria from taproots, cold-stored taproots, and in vitro-grown tissue cultures contain a functional NADH dehydrogenase, whereas only those isolated from tissue cultures displayed a functional NAD(P)H dehydrogenase. It is interesting that the NADH-dependent [delta][psi] of mitochondria from cold-stored taproots and from tissue cultures was not affected by free Ca2+ ions, whereas free Ca2+ was required for the mitochondrial NADPH oxidation by in vitro-grown cells and cytosolic NADH oxidation by mitochondria from fresh taproots. A tentative model accounting for the different response to Ca2+ ions of the NADH dehydrogenase in mitochondria from cold-stored taproots and tissue cultures of B. vulgaris is discussed