Mass propagation through direct and indirect organogenesis in three species of genus Zephyranthes and ploidy assessment of regenerants through flow cytometry.

Genus Zephyranthes consists of economically important plant species due to their high ornamental value and presence of valuable bioactive compounds. However, this genus propagates by asexual division only which gives slow propagation rate. Plant tissue culture has the potential to provide efficient techniques for rapid multiplication and genetic improvement of the genus. In this work, a dual in vitro regeneration system through callus mediated shoot regeneration and direct shoot regeneration in species Zephyranthes candida, Zephyranthes grandiflora and Zephyranthes citrina was investigated. Bulb, leaf and root explants were cultured on Murashige and Skoog (MS) medium amended with different plant growth regulators (PGR's) viz. 2,4-dichlorophenoxyacetic acid (2,4-D), 1-Naphthalene acetic acid (NAA), 6-benzyl amino purine (BAP), N-phenyl-N'-1,2,3 -thiadiazol-5-ylurea (TDZ), 6-Furfuryl- aminopurine (KIN) alone or in combinations for callus induction and regeneration. Only bulb explants showed callus induction and regeneration response on different PGR combinations with a varied response in callus induction percentage, callus color and callus texture. Creamish compact callus (CC) was induced on 2 mg L[Formula: see text] 2,4-D, brown friable callus (BF) on 2 mg L[Formula: see text] NAA + 1 mg L[Formula: see text] BAP and green friable callus (GF) callus on 1 mg L[Formula: see text] KIN + 3 mg L[Formula: see text] NAA. The maximum shoot multiplication from different callus types (indirect organogenesis) was achieved on 2 mg L[Formula: see text] BAP alone without combinations. Bulb explants of Z. grandiflora induced maximum callus induction percentage (86.4%) and shoot regeneration percentage (83.5%) with the maximum 08 shoots per 150 mg callus mass. The induction and regeneration response was followed in the order of Z. grandiflora > Z. candida > Z. citrina. Similarly, maximum direct organogenesis from bulb explants was obtained in Z. grandiflora (93.3%) followed by Z. candida (91.5%) and Z. citrina (90.4%) on 3 mg L[Formula: see text] TDZ amended MS media. Adventitious root induction was achieved on 2 mg L[Formula: see text] IBA with a maximum of 8 roots per shoot. The in vitro raised plantlets were successfully acclimatized in the field with 85% survival efficiency. The genome size (2C DNA content) of the field-grown plants and in vitro regenerated plants, evaluated through flow cytometry technique, were similar and showed no ploidy changes. An efficient mass propagation protocol was established for obtaining plants with unaltered genome size in the three species of Zephyranthes.

Azolla domestication towards a biobased economy?

Due to its phenomenal growth requiring neither nitrogen fertilizer nor arable land and its biomass composition, the mosquito fern Azolla is a candidate crop to yield food, fuels and chemicals sustainably. To advance Azolla domestication, we research its dissemination, storage and transcriptome. Methods for dissemination, cross-fertilization and cryopreservation of the symbiosis Azolla filiculoides-Nostoc azollae are tested based on the fern spores. To study molecular processes in Azolla including spore induction, a database of 37 649 unigenes from RNAseq of microsporocarps, megasporocarps and sporophytes was assembled, then validated. Spores obtained year-round germinated in vitro within 26 d. In vitro fertilization rates reached 25%. Cryopreservation permitted storage for at least 7 months. The unigene database entirely covered central metabolism and to a large degree covered cellular processes and regulatory networks. Analysis of genes engaged in transition to sexual reproduction revealed a FLOWERING LOCUS T-like protein in ferns with special features induced in sporulating Azolla fronds. Although domestication of a fern-cyanobacteria symbiosis may seem a daunting task, we conclude that the time is ripe and that results generated will serve to more widely access biochemicals in fern biomass for a biobased economy.

Shoot organogenesis from root-derived callus of Rhinacanthus nasutus (L.) Kurz. and assessment of clonal fidelity of micropropagted plants using RAPD analysis.

An efficient regeneration system was established for an ethnomedicinal shrub Rhinacanthus nasutus from root-derived callus organogenesis. The root segments were cultured on MS medium supplemented with various concentrations of Kn (1.0-4.0 µM) alone or in combination with IBA (0.2-0.6 µM) or 2, 4-D (0.5-1.5 µM). The optimum frequency (94%) of callus induction was recorded on MS medium supplemented with 3.0 µM Kn and 0.4 µM IBA. For shoot regeneration from callus, MS medium supplemented with different concentrations (1.0-7.0 µM) of BA or TDZ alone or in combination with NAA (0.2-1.0 µm) was employed. The highest frequency of shoot regeneration (91%) and mean number of shoots (28.3) were observed on MS medium supplemented with 5.0 µM BA and 0.7 µM NAA. The shoots were excised and cultured on MS medium with 4.0 µM IBA produced 3.4 roots per shoot in 88% cultures. Of the 65 plants transferred to soil 54 survived (83%). The plants were transferred to field after successful hardening. RAPD analysis of the regenerated plants showed high similarity with the mother plant.

Genome-wide computational function prediction of Arabidopsis proteins by integration of multiple data sources.

Although Arabidopsis (Arabidopsis thaliana) is the best studied plant species, the biological role of one-third of its proteins is still unknown. We developed a probabilistic protein function prediction method that integrates information from sequences, protein-protein interactions, and gene expression. The method was applied to proteins from Arabidopsis. Evaluation of prediction performance showed that our method has improved performance compared with single source-based prediction approaches and two existing integration approaches. An innovative feature of our method is that it enables transfer of functional information between proteins that are not directly associated with each other. We provide novel function predictions for 5,807 proteins. Recent experimental studies confirmed several of the predictions. We highlight these in detail for proteins predicted to be involved in flowering and floral organ development.