Tuberization is one of the multiple outputs of a single-input phytochrome B sensory system, involving several regulatory genes. Phytochrome B- and GA-mediated photoperiodic perception occurs in the leaf, and then the RNA acts as a systemic signal in the long-distance signaling pathway to initiate tuberization in the subapical region of an underground stolon. There is good evidence that flowering and tuberizing signals might be similar. Is there a cross-talk with an oxidative burst-mediated redox signaling pathway during tuberization? Is the lipoxygenase cascade involved in the formation of the perimedullary tissue in a growing tuber? Do aquaporins regulate cell division, expansion and elongation during stolon growth and tuber induction in potato? Is the adaptive diversity for tuberization under varying photoperiods a micro-evolutionary indicator of differential transduction of cell-to-cell signal molecules under spatial and temporal expression of regulatory genes encoding transcriptional activators? Taking these views into consideration, the review presents an interim synthesis of a signaling network regulating in planta tuberization in potato.

We generated the bast transcriptomes of a deficient lignified phloem fibre mutant and its wild-type jute (Corchorus capsularis) using Illumina paired-end sequencing. A total of 34,163 wild-type and 29,463 mutant unigenes, with average lengths of 1442 and 1136 bp, respectively, were assembled de novo, ~77-79 % of which were functionally annotated. These annotated unigenes were assigned to COG (~37-40 %) and GO (~22-28 %) classifications and mapped to 189 KEGG pathways (~19-21 %). We discovered 38 and 43 isoforms of 16 and 10 genes of the upstream shikimate-aromatic amino acid and downstream monolignol biosynthetic pathways, respectively, rendered their sequence similarities, confirmed the identities of 22 of these candidate gene families by phylogenetic analyses and reconstructed the pathway leading to lignin biosynthesis in jute fibres. We also identified major genes and bast-related transcription factors involved in secondary cell wall (SCW) formation. The quantitative RT-PCRs revealed that phenylalanine ammonia-lyase 1 (CcPAL1) was co-down-regulated with several genes of the upstream shikimate pathway in mutant bast tissues at an early growth stage, although its expression relapsed to the normal level at the later growth stage. However, cinnamyl alcohol dehydrogenase 7 (CcCAD7) was strongly down-regulated in mutant bast tissues irrespective of growth stages. CcCAD7 disruption at an early growth stage was accompanied by co-up-regulation of SCW-specific genes cellulose synthase A7 (CcCesA7) and fasciclin-like arabinogalactan 6 (CcFLA6), which was predicted to be involved in coordinating the S-layers' deposition in the xylan-type jute fibres. Our results identified CAD as a promising target for developing low-lignin jute fibres using genomics-assisted molecular approaches.

Jute is an important natural fibre crop, which is only second to cotton in its importance at the global level. It is mostly grown in Indian subcontinent and has been recently used for the development of genomics resources.We recently initiated a programme to develop simple sequence repeat markers and reported a set of 2469 SSR that were developed using four SSR-enriched libraries (Mir et al. 2009). In this communication, we report an additional set of 607 novel SSR in 393 SSR containing sequences. However, primers could be designed for only 417 potentially useful SSR. Polymorphism survey was carried out for 374 primer pairs using two parental genotypes (JRO 524 and PPO4) of a mapping population developed for fibre fineness; only 66 SSR were polymorphic. Owing to a low level of polymorphism between the parental genotypes and a high degree of segregation distortion in recombinant inbred lines, genotypic data of only 53 polymorphic SSR on the mapping population consisting of 120 RIL could be used for the construction of a linkage map; 36 SSR loci were mapped on six linkage groups that covered a total genetic distance of 784.3 cM. Hopefully, this map will be enriched with more SSR loci in future and will prove useful for identification of quantitative trait loci/genes for molecular breeding involving improvement of fibre fineness and other related traits in jute.

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The effects of jasmonic acid (JA) and methyl jasmonate (MeJA) on potato (Solanum tuberosum L.) tuberization were studied in relation to cytokinins using single-node cuttings (SNCs) in vitro. In three potato cultivars differing in maturity levels, JA or MeJA (0.0, 2.5, 5.0, 7.5 and 10.0 lM) action was examined with N 6 -benzyladenine (BA: 0.0, 22.0 and 44.0 lM) under optimum tuber-inducing treatment with 80 g L -1 sucrose. Although jasmonates had a stimulatory role in root growth from SNCs, BA inhibited the root growth and antagonized the jasmonates action on root growth promotion. There was a strong inhibitory effect of BA on stoloniferous shoot growth, and in combination with jasmonates it could exert a much pronounced inhibitory effect. Jasmonates did not have any role in tuber induction in terms of tuber number and sourcesink coordination (harvest index), rather their effects were counteracted in the presence of 22.0 lM BA in early cultivar. However, they had a promoting effect on tuber growth after induction in early cultivar, possibly due to its lower levels of endogenous gibberellins.Cytokinins detrimentally affected the tuber growth, and antagonized the jasmonates action irrespective of the maturity levels of the cultivars. It could, however, increase the tuber dry matter concomitant with a higher accumulation of starch. The promoting effect of jasmonates on tuber dry matter and starch accumulation was apparent only in early cultivar. There were significant interactions between cytokinin and jasmonates for accumulation of reducing and total sugars in tubers. The results show that exogenous cytokinins antagonize the jasmonates action, and the correlated effects of these two growth hormones interact with the maturing time of the cultivar during potato tuber formation in vitro.

Flood is a natural but inevitable phenomenon occurring over the period of time. It not only damages the life, property and resources, but also hampers the economy of a nation. In this paper, an attempt has been made to delineate flood vulnerability areas for Kulik river basin through frequency ratio model. Parameters like slope, elevation, rainfall, drainage density, land use-land cover, TWI, population density, road density and household density were endorsed for understanding flood mechanism. In general, 70 (70%) flood locations from flood inventory map were randomly selected for constructing flood vulnerability map parameters and the rest 30 (30%) flood locations were used for justifying the outcomes. Flood vulnerability zone map was classified into five zones such as very low (2.02 km 2 ), low (2.45 km 2 ), moderately low (2.44 km 2 ), high vulnerable (2.26 km 2 ) and very high vulnerable (1.21 km 2 ) area. As the AUC value for success rate is 0.901, the constructed flood vulnerable map with FR model is very much accurate for this river basin. The outcome of this paper will help the planners and decision-makers to take some probable measure to minimize flood vulnerability in this region.

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