The functional role of rice (Oryza sativa) germin-like protein1 (OsGLP1) was elucidated through development of transgenic plants involving endogenous gene silencing in rice and heterologous gene expression in tobacco. Usually, the single copy OsGLP1 gene in rice plant was found to be expressed predominantly in green vegetative tissues. The transgenic rice lines showed significant reduction in endogenous OsGLP1 expression due to 26 nt siRNA-mediated gene silencing, displayed semi-dwarfism and were affected seriously by fungal diseases, compared to the untransformed plant. Structural homology modeling predicted a superoxide dismutase (SOD) domain in OsGLP1 protein which upon over-expression in transgenic tobacco plant clearly documented SOD activity. Our observations on the maintenance of cell dimension, cell wall-associated localization particularly in the sub-epidermal tissues and the SOD activity of OsGLP1 could explain its functional role in regulation of plant height and disease resistance in rice plant.

Our recent report documented that the rice germin-like protein1 (OsGLP1), being a cell wall-associated protein involves in disease resistance in rice and possesses superoxide dismutase (SOD) activity as recognized by heterologous expression in tobacco. In the present study, the transgenic tobacco plants were analyzed further to decipher the detailed physiological and biochemical functions of the OsGLP1 and its associated SOD activity. The transgenic tobacco lines expressing SOD-active OsGLP1 showed tolerance against biotic and abiotic stresses mitigated by hyper-accumulating H 2 O 2 upon infection by fungal pathogen (Fusarium solani) and treatment to chemical oxidizing agent (ammonium persulfate), respectively. Histological staining revealed enhanced cross-linking of the cell wall components in the stem tissues of the transgenic plants. Fourier transform infrared spectroscopy (FTIR) analysis of the biopolymer from the stem tissues of the transgenic and untransformed plants revealed differential banding pattern of the spectra corresponding to various functional groups. Our findings demonstrate that the OsGLP1 with its inherent SOD activity is responsible for hyper-accumulation of H 2 O 2 and reinforcement of the cell wall components.

An efficient protocol for shoot regeneration was developed for sesame (Sesamum indicum L.) internodes using the transverse thin cell layer (tTCL) culture method. The frequency of shoot regeneration and the number of adventitious buds produced from regenerated shoots depend significantly on explant age, thickness of the tTCL sections, and the phytohormones supplemented to the culture medium. A combination of 6-benzyladenine (2.0 mg l -1 ) and a-naphthaleneacetic acid (0.5 mg l -1 ) was found to be the best phytohormone combination for shoot bud induction, with the maximum number of shoots obtained when the tTCL sections were 0.5-1.0 mm thick and derived from 4-to 6-week-old seedlings of sesame. Well-developed shoots were rooted on MS medium without phytohormones, and 80% of the regenerated plantlets were successfully established in soil.

Lipid accumulation abilities of two endophytic fungal isolates -Colletotrichum sp. and Alternaria sp. grown under optimum and nutrient-stress conditions were investigated and compared. Significant variations in lipid contents, ranging from 30% to 58% of their dry biomass were found in liquid culture using various carbon sources. Since, >50% of the total lipid was estimated to be neutral lipid for both the fungal species, predicted biodiesel properties were theoretically calculated based upon the determined fatty acid profiles; and the values were found to be comparable to those of commonly used plant oils for biodiesel production. The two endophytes grew successfully on the combined rice straw and wheat bran as substrate that was degraded by their secretory enzymes including cellulase [1.21-2.51 FPU/g dry substrate (gds)] in solid state fermentation and produced substantial amount of lipid (60.32-84.30 mg/ gds). Our study highlights the potential utilities of these two novel endophytic fungi as biodiesel feedstock.

Calmodulin N-methyltransferase (CaM KMT) is an evolutionarily conserved enzyme in eukaryotes that transfers three methyl groups to a highly conserved lysyl residue at position 115 in calmodulin (CaM). We sought to elucidate whether the methylation status of CaM plays a role in CaM-mediated signaling pathways by gene expression analyses of CaM KMT and phenotypic characterization of Arabidopsis thaliana lines wherein CaM KMT was overexpressed (OX), partially silenced, or knocked out. CaM KMT was expressed in discreet spatial and tissue-specific patterns, most notably in root tips, floral buds, stamens, apical meristems, and germinating seeds. Analysis of transgenic plants with genetic dysfunction in CaM KMT revealed a link between the methylation status of CaM and root length. Plants with suppressed CaM methylation had longer roots and CaM KMT OX lines had shorter roots than wild type (Columbia-0). CaM KMT was also found to influence the root radial developmental program. Protein microarray analyses revealed a number of proteins with specificity for methylated forms of CaM, providing candidate functional intermediates between the observed phenotypes and the target pathways. This work demonstrates that the functionality of the large CaM family in plants is fine-tuned by an overarching methylation mechanism.

On chromosome 4 in the Arabidopsis genome, two neighboring genes (calmodulin methyl transferase At4g35987 and senescence associated gene At4g35985) are located in a head-to-head divergent orientation sharing a putative bidirectional promoter. This 1258 bp intergenic region contains a number of environmental stress responsive and tissue specific cisregulatory elements. Transcript analysis of At4g35985 and At4g35987 genes by quantitative real time PCR showed tissue specific and stress inducible expression profiles. We tested the bidirectional promoter-function of the intergenic region shared by the divergent genes At4g35985 and At4g35987 using two reporter genes (GFP and GUS) in both orientations in transient tobacco protoplast and Agro-infiltration assays, as well as in stably transformed transgenic Arabidopsis and tobacco plants. In transient assays with GFP and GUS reporter genes the At4g35985 promoter (P85) showed stronger expression (about 3.5 fold) compared to the At4g35987 promoter (P87). The tissue specific as well as stress responsive functional nature of the bidirectional promoter was evaluated in independent transgenic Arabidopsis and tobacco lines. Expression of P85 activity was detected in the midrib of leaves, leaf trichomes, apical meristemic regions, throughout the root, lateral roots and flowers. The expression of P87 was observed in leaf-tip, hydathodes, apical meristem, root tips, emerging lateral root tips, root stele region and in floral tissues. The bidirectional promoter in both orientations shows differential up-regulation (2.5 to 3 fold) under salt stress. Use of such regulatory elements of bidirectional promoters showing spatial and stress inducible promoter-functions in heterologous system might be an important tool for plant biotechnology and gene stacking applications.

A subgenomic transcript (Sgt) promoter was isolated from the genomic clone of dahlia mosaic virus (DaMV), which is a double-stranded DNA virus of the Caulimoviridae family. The DaMVSgt promoter, which is linked to the heterologous β-glucuronidase (GUS) reporter gene, was characterized in transient protoplasts and in transgenic tobacco, as well as in Arabidopsis plants. The 5′-and 3′-deletion analysis of a 591-bp DaMVSgt promoter fragment indicated that a 441-bp promoter fragment (−372 to +69 from the transcription start site; TSS) was sufficient for maximal promoter activity. A 141-bp promoter fragment (−72 to +69 from TSS) was the minimal promoter region that also showed relatively strong activity. The three activation sequence-1 (as-1) elements and the border regions were primarily responsible for the promoter activity, as revealed by a finer internal deletion and mutation analysis of the cis-elements and of the immediate border sequence of the activation domain. Electrophoretic mobility shift assay (EMSA), supershift EMSA, DNase I footprinting, Southwestern blotting, and UV cross-linking studies demonstrated the binding of a tobacco transcription factor, TGA1a, that correlated with 2,4-dichlorophenylacetic acid (2,4D)-induced transcriptional activity of the DaMVSgt promoter. Histological GUS staining and the GUS enzymatic assay demonstrated that the 441-bp DaMVSgt4 promoter and 141bp minimal DaMVSgt4F are 5.5 and 4.6 times, respectively, stronger than the CaMV 35S promoter. The minimal DaMVSgt4F promoter is more active than CaMV 35S in all types of green tissues and roots, without any detectable expression in reproductive tissues and seeds. The DaMVSgt4F promoter may be useful for transgene containment applications.

A number of dioecious species are grown across India and some of those plants play a crucial role in the agro-based economy of the country. The diagnosis of sex is very difficult in the dioecious plant prior flowering wherein sex identification at the seedling stage is of great importance to breeders as well as farmers for crop improvement or production purpose. A comprehensive approach of sex determination comprising morphological, biochemical, cytological and molecular attributes is a must required for gender differentiation in dioecious plant species. In the present review, we highlighted the economical, medicinal as well as industrial importance of most of the dioecious species extensively grown in Indian subcontinent. In addition to that, the cytogenetic, genetic as well as molecular information in connection to their sex determination were critically discussed in this review.

Low phosphorus (P) availability is the major abiotic constraint in chickpea (Cicer arietinum L.) cultivation across the globe as well as in India. Present study contemplated to identify high P-acquisition efficient chickpea genotypes suitable for P-deficient regions and sequence variation was detected among the tested P-acquisition efficient and inefficient genotypes. Initial screening was conducted with 104 diverse chickpea genotypes at two locations characterized by P-sufficient and deficient conditions. A panel of 14 chickpea genotypes having contrasting P-acquisition efficiency was extracted for further assessment under P-sufficient and deficient conditions. Along with the significant genetic variations, the P-efficient chickpea genotypes had high P-acquisition efficiency than P-inefficient genotypes in both the conditions. P-acquisition efficient genotypes recorded high biomass and good yield potential in P-deficient condition in comparison to P-inefficient genotypes. Sequence ...

The plant rhizosphere interfaces an array of microbiomes related to plant growth and development. Cultivar-specific soil microbial communities with respect to their taxonomic structure and specific function have not been investigated explicitly in improving the adaptation of lentil cultivars under rice-fallow ecology. The present study was carried out to decipher the rhizosphere microbiome assembly of two lentil cultivars under rice-fallow ecology for discerning the diversity of microbial communities and for predicting the function of microbiome genes related to nitrogen (N) and phosphorus (P) cycling processes deploying high-throughput whole (meta) genome sequencing. The metagenome profile of two cultivars detected variable microbiome composition with discrete metabolic activity. Cyanobacteria, Bacteroidetes, Proteobacteria, Gemmatimonadetes, and Thaumarchaeota were abundant phyla in the “Farmer-2” rhizosphere, whereas Actinobacteria, Acidobacteria, Firmicutes, Planctomycetes, Chlo...