A Rapid Protocol for Somatic Embryogenesis Mediated Regeneration in Banana (Musa Spp.) Cv. Nendran

A simple and rapid protocol for somatic embryogenesis in banana cv. Nendran (AAB) using immature male flowers (IMF) has been developed. The IMF produced palewhite to yellow, globular embryogenic callus on MS medium supplemented with BA (0.05 - 0.50mgL-1) and picloram (0.50 - 2.00mgL-1) with explant response of to 30 per cent. Addition of ascorbic acid (20mgL-1) and Gelrite© (0.45 per cent) to callus induction medium reduced interference from phenolic exudation. Embryogenesis was induced (33.3 to 60 per cent) on semisolid (0.30 per cent Gelrite©) MS medium supplemented with BA 2mgL-1 + IAA 0.5mgL-1. The somatic embryos showed 60-80 per cent germination on half- strength semisolid MS medium with BA 2mgL-1 + IAA 0.5mgL-1. Transfer of germinated embryos to semisolid MS medium supplemented with BA 2mgL-1 + NAA 1mgL-1under 14 h light /8h dark photoperiod resulted in hundred percent conversion to plantlets. This protocol takes merely 6 months for producing plantlets from immature flower buds through somatic embryogenesis, without any intermediate liquid cultures

Short day transcriptomic programming during induction of dormancy in grapevine

Bud dormancy in grapevine is an adaptive strategy for the survival of drought, high and low temperatures and freeze dehydration stress that limit the range of cultivar adaptation. Therefore, development of a comprehensive understanding of the biological mechanisms involved in bud dormancy is needed to promote advances in selection and breeding, and to develop improved cultural practices for existing grape cultivars. The seasonally indeterminate grapevine, which continuously develops compound axillary buds during the growing season, provides an excellent system for dissecting dormancy, because the grapevine does not transition through terminal bud development prior to dormancy. This study used gene expression patterns and targeted metabolite analysis of two grapevine genotypes that are short photoperiod responsive (Vitis riparia) and non-responsive (V. hybrid, Seyval) for dormancy development to determine differences between bud maturation and dormancy commitment. Grapevine gene expression and metabolites were monitored at seven time points under long (LD, 15 h) and short (SD, 13 h) day treatments. The use of age-matched buds and a small (2 h) photoperiod difference minimized developmental differences and allowed us to separate general photoperiod from dormancy specific gene responses. Gene expression profiles indicated three distinct phases (perception, induction and dormancy) in SD-induced dormancy development in V. riparia. Different genes from the NAC DOMAIN CONTAINING PROTEIN 19 and WRKY families of transcription factors were differentially expressed in each phase of dormancy. Metabolite and transcriptome analyses indicated ABA, trehalose, raffinose and resveratrol compounds have a potential role in dormancy commitment. Finally, a comparison between V. riparia compound axillary bud dormancy and dormancy responses in other species emphasized the relationship between dormancy and the expression of RESVERATROL SYNTHASE and genes associated with C3HC4-TYPE RING FINGER and NAC DOMAIN CONTAINING PROTEIN 19 transcription factors.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Frontiers. The published article can be found at: http://journal.frontiersin.org/journal/plant-science. The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fpls.2015.00834Keywords: resveratrol, Seyval, Vitis riparia, ABA, bud, VitisNet, raffinose, trehalos

Characterization of Vitis vinifera L. somatic variants exhibiting abnormal flower development patterns

Mutants have proven to be a key resource for functional genomic studies in model annual plant species. In perennial plant species where mutants are difficult to generate and to screen, spontaneous somatic variants represent a unique resource to understand the genetic control of complex developmental patterns. The morphological and histological characterization of six Vitis vinifera L. somatic variants that display four different abnormal phenotypes of flower development are described here. A phenotype of reiterated reproductive meristems (RRM), with both flower and petal reiteration, was observed in a somatic variant of the cultivar Carignan. An abnormal development of reproductive organs was displayed by the unfused carpels (UFC) somatic variant of cv. Bouchalès, while a somatic variant of cv. Mourvèdre named carpel-less (CLS) developed abnormal ovules in the absence of carpels. Finally, three independent somatic variants in cvs Gamay, Morrastel, and Pinot displayed a phenotype of multiple perianth whorls (MPW). Gene expression studies showed that the expression profiles of VvMADS-box 1, 2, and 3 (putative orthologues of Arabidopsis flowering genes AG, SEP, and AGL13), were altered during grapevine flower development in the somatic variants, whereas the corresponding original cultivars displayed similar VvMADS-box gene expression profiles. Phenotypic and molecular characterization of these variants allowed the development of hypotheses on genetic functions that might be altered in most of the variants in light of the current ABCDE flower modelPeer reviewe

Differential floral development and gene expression in grapevines during long and short photoperiods suggests a role for floral genes in dormancy transitioning

Daylength is an important environmental cue for synchronizing growth, flowering, and dormancy with seasonality. As many floral development genes are photoperiod regulated, it has been suggested that they could have a regulatory role in bud endodormancy. Therefore, the influence of photoperiod was studied on inflorescence primordia differentiation and floral pathway related gene expression during the development of overwintering buds in Vitis riparia and V. spp. ‘Seyval’. Photoperiod treatments were imposed 35 days after budbreak, and histological and transcriptomic analyses were conducted during the subsequent 42 days of bud development. Long day (LD, 15 h) and short day (SD, 13 h) buds were floral competent by 21 days of photoperiod treatment (56 days after budbreak); however, the floral meristem developed faster in LD than in SD buds. Analysis of 132 floral pathway related genes represented on the Affymetrix Grape Genome array indicated 60 were significantly differentially expressed between photoperiod treatments. Genes predominantly related to floral transition or floral meristem development were identified by their association with distinct grape floral meristem development and an expression pattern in LD consistent with their previously identified roles in flowering literature. Genes with a potential dual role in floral development and dormancy transitioning were identified using photoperiod induced differences in floral development between LD and SD buds and uncharacteristic gene expression trends in relation to floral development. Candidate genes with the potential to play a dual role in SD dormancy induction include circadian rhythm or flowering transition related genes: AP2, BT1, COL-13, EIN3, ELF4, DDTR, GAI and HY5.This work was funded by the National Science Foundation (NSF) Plant Genome Program DBI0604755 and South Dakota State University Agricultural Experiment Station. The South Dakota State University Functional Genomics Core Facility, supported in part by the NSF funding EPSCoR0091948, was used to conduct histological analysis.Peer reviewe

Short day transcriptomic programming during induction of dormancy in grapevine

Bud dormancy in grapevine is an adaptive strategy for the survival of drought, high and low temperatures and freeze dehydration stress that limit the range of cultivar adaptation. Therefore, development of a comprehensive understanding of the biological mechanisms involved in bud dormancy is needed to promote advances in selection and breeding, and to develop improved cultural practices for existing grape cultivars. The seasonally indeterminate grapevine, which continuously develops compound axillary buds during the growing season, provides an excellent system for dissecting dormancy, because the grapevine does not transition through terminal bud development prior to dormancy. This study used gene expression patterns and targeted metabolite analysis of two grapevine genotypes that are short photoperiod responsive (Vitis riparia) and non-responsive (V. hybrid, Seyval) for dormancy development to determine differences between bud maturation and dormancy commitment. Grapevine gene expression and metabolites were monitored at seven time points under long (LD, 15 h) and short (SD, 13 h) day treatments. The use of age-matched buds and a small (2 h) photoperiod difference minimized developmental differences and allowed us to separate general photoperiod from dormancy specific gene responses. Gene expression profiles indicated three distinct phases (perception, induction and dormancy) in SD-induced dormancy development in V. riparia. Different genes from the NAC DOMAIN CONTAINING PROTEIN 19 and WRKY families of transcription factors were differentially expressed in each phase of dormancy. Metabolite and transcriptome analyses indicated ABA, trehalose, raffinose and resveratrol compounds have a potential role in dormancy commitment. Finally, a comparison between V. riparia compound axillary bud dormancy and dormancy responses in other species emphasized the relationship between dormancy and the expression of RESVERATROL SYNTHASE and genes associated with C3HC4-TYPE RING FINGER and NAC DOMAIN CONTAINING PROTEIN 19 transcription factors.This work was supported by National Science Foundation Plant Genome Research Grant DBI0604755, South Dakota State University Experiment Station and the South Dakota State University Functional Genomics Core Facility and the University of Nevada, Reno Proteomics Center. The Nevada Proteomics Center and the Nevada Center for Bioinformatics are supported by a grant from the National Institute of General Medical Sciences (P20GM103440).Peer Reviewe

Presence of integrase core domain in mutant type black pepper Piper nigrum L. ‘Thekken’ with altered inflorescence architecture

770-773Black pepper (Piper nigrum L.), referred as the ‘King of Spices’, is native to India and has shown declined productivity over the years. It exhibits diverse quantitative and qualitative traits, particularly in spike length, floral composition, floral arrangement, fruit size and number. The novel mutant variety of black pepper (Piper nigrum L.) ‘Thekken’ shows a remarkable branching character in the spikes. In the present study, we analyzed RAMOSA3 (RA3) gene at the molecular level in this variety for yield improvement. Screening using degenerate primers designed for RA3 was carried out in ‘Thekken’ and a non-branching variety ‘Karimunda’ at the genomic level and at different stages of spike development at the transcriptome level. Sequence analysis of the amplicons generated in RT-PCR revealed the presence of an integrase core domain in the mutant type of black pepper, suggesting a possibility of mutation at this locus in the branched variety due to retrotransposon integration. The study suggests a possibility for introgression of the genes responsible for branching trait from the mutant variety of black pepper type ‘Thekken’ to other conventional cultivated varieties of black pepper that show single unbranched spike thereby increasing the productivity of black pepper which has very high economic value and export potential

Bioethanol production from watermelon rind by fermentation using <em>Saccharomyces cerevisiae</em> and <em>Zymomonas mobilis</em>

663-666Bioethanol production potential of watermelon rind as feed stock was studied using Saccharomyces cerevisiae and Zymomonas mobilis. Significant production (5.86%) of bioethanol could be obtained at a five per cent substrate concentration of watermelon rind along with peptone as an additive by carrying out a single batch bioconversion and fermentation. The use of Zymomonas mobilis for saccharification and Saccharomyces cerevisiae for fermentation was found to be more effective compared to the use of single organisms for both the steps. The efficacy of bioconversion by Zymomonas mobilis was confirmed by the reduction in cellulose content of the biomass and increase in the total reducing sugar content (490 µg/ml) and glucose content (0.09%)

Identification of genes associated with flesh morphogenesis during grapevine fruit development

UMR DAP, équipe AFEFInternational audienceFruit morphogenesis is a process unique to the angiosperms, and yet little is known about its developmental control. Following fertilization, fruits typically undergo a dramatic enlargement that is accompanied by differentiation of numerous distinct cell types. To identify genes putatively involved in the early development of grapevine fruit, we used the fleshless berry mutant (Vitis vinifera L. cv Ugni Blanc) that has dramatically reduced fruit size due to a lack of pericarp development. Using oligo-specific arrays, 53 and 50 genes were identified as being down- and up-regulated, respectively, in the mutant. In parallel, Suppression Subtractive Hybridization performed between the mutant and the wild type (WT) allowed the identification of new transcripts differentially expressed during the first stages of mutant and WT pericarp development. From this data, the picture emerged that the mutation promotes the expression of several genes related to ripening and/or to stress and impairs the expression of several regulatory genes. Among those, five genes encoding proteins previously reported to be associated with, or involved in, developmental processes in other species (a specific tissue protein 2, ATHB13, a BURP domain protein, PISTILLATA, and YABBY2), were identified and investigated further using real-time PCR and in situ hybridization. Expression in the pericarp was confirmed, specific spatial and/or temporal patterns were detected and differences were observed between the WT and the mutant during fruit development. Expression of these genes appeared to be affected during young fruit development in the mutant, suggesting that they may play a role in grape berry morphogenesi