Isolation and functional characterization of Lycopene β-cyclase (CYC-B) promoter from Solanum habrochaites

<p>Abstract</p> <p>Background</p> <p>Carotenoids are a group of C40 isoprenoid molecules that play diverse biological and ecological roles in plants. Tomato is an important vegetable in human diet and provides the vitamin A precursor <it>β</it>-carotene. Genes encoding enzymes involved in carotenoid biosynthetic pathway have been cloned. However, regulation of genes involved in carotenoid biosynthetic pathway and accumulation of specific carotenoid in chromoplasts are not well understood. One of the approaches to understand regulation of carotenoid metabolism is to characterize the promoters of genes encoding proteins involved in carotenoid metabolism. <it>Lycopene β-cyclase </it>is one of the crucial enzymes in carotenoid biosynthesis pathway in plants. Its activity is required for synthesis of both α-and β-carotenes that are further converted into other carotenoids such as lutein, zeaxanthin, etc. This study describes the isolation and characterization of chromoplast-specific <it>Lycopene β-cyclase </it>(<it>CYC-B</it>) promoter from a green fruited <it>S. habrochaites </it>genotype EC520061.</p> <p>Results</p> <p>A 908 bp region upstream to the initiation codon of the <it>Lycopene β-cyclase </it>gene was cloned and identified as full-length promoter. To identify promoter region necessary for regulating developmental expression of the <it>ShCYC-B </it>gene, the full-length promoter and its three different 5' truncated fragments were cloned upstream to the initiation codon of <it>GUS </it>reporter cDNA in binary vectors. These four plant transformation vectors were separately transformed in to <it>Agrobacterium</it>. <it>Agrobacterium</it>-mediated transient and stable expression systems were used to study the <it>GUS </it>expression driven by the full-length promoter and its 5' deletion fragments in tomato. The full-length promoter showed a basal level activity in leaves, and its expression was upregulated > 5-fold in flowers and fruits in transgenic tomato plants. Deletion of -908 to -577 bp 5' to ATG decreases the <it>ShCYC-B </it>promoter strength, while deletion of -908 to -437 bp 5' to ATG led to significant increase in the activity of GUS in the transgenic plants. Promoter deletion analysis led to the identification of a short promoter region (-436 bp to ATG) that exhibited a higher promoter strength but similar developmental expression pattern as compared with the full-length <it>ShCYC-B </it>promoter.</p> <p>Conclusion</p> <p>Functional characterization of the full-length <it>ShCYC-B </it>promoter and its deletion fragments in transient expression system <it>in fruto </it>as well as in stable transgenic tomato revealed that the promoter is developmentally regulated and its expression is upregulated in chromoplast-rich flowers and fruits. Our study identified a short promoter region with functional activity and developmental expression pattern similar to that of the full-length <it>ShCYC-B </it>promoter. This 436 bp promoter region can be used in promoter::reporter fusion molecular genetic screens to identify mutants impaired in <it>CYC-B </it>expression, and thus can be a valuable tool in understanding carotenoid metabolism in tomato. Moreover, this short promoter region of <it>ShCYC-B </it>may be useful in genetic engineering of carotenoid content and other agronomic traits in tomato fruits.</p

SSR and AFLP based genetic diversity of soybean germplasm differing in photoperiod sensitivity

Forty-four soybean genotypes with different photoperiod response were selected after screening of 1000 soybean accessions under artificial condition and were profiled using 40 SSR and 5 AFLP primer pairs. The average polymorphism information content (PIC) for SSR and AFLP marker systems was 0.507 and 0.120, respectively. Clustering of genotypes was done using UPGMA method for SSR and AFLP and correlation was 0.337 and 0.504, respectively. Mantel's correlation coefficients between Jaccard's similarity coefficient and the cophenetic values were fairly high in both the marker systems (SSR = 0.924; AFLP = 0.958) indicating very good fit for the clustering pattern. UPGMA based cluster analysis classified soybean genotypes into four major groups with fairly moderate bootstrap support. These major clusters corresponded with the photoperiod response and place of origin. The results indicate that the photoperiod insensitive genotypes, 11/2/1939 (EC 325097) and MACS 330 would be better choice for broadening the genetic base of soybean for this trait

Multilateral benefit-sharing from digital sequence information will support both science and biodiversity conservation

Open access to sequence data is a cornerstone of biology and biodiversity research, but has created tension under the United Nations Convention on Biological Diversity (CBD). Policy decisions could compromise research and development, unless a practical multilateral solution is implemented.This workwas funded by the German Federal Ministry of Education and Research (BMBF) WiLDSI 031B0862 (A.H.S., J.O., and J.F.) and Horizon Europe EVA-GLOBAL 871029 (A.H.S.). I.K.M. was supported by the National Center for Biotechnology Information of the National Library of Medicine, National Institutes of Health

A road map for implementing the multilateral system of access and benefit-sharing in India

This is a collection of 14 papers addressing a range of issues that are important to consider as India develops its strategy for implementing the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA), and its multilateral system of access and benefit sharing in particular. The papers consider, among other things: flows of plant genetic resources into and out of India; the state of PGRFA conservation and use in India; the rationale for India’s deciding to ratify the ITPGRFA in the first place; whether or not there is legal space to implement the multilateral system in India; linkages between community seed banks and the multilateral system; linkages with efforts to implement the Convention on Biological Diversity in India; how the multilateral system can provide support for efforts in India to exploit crop diversity to adapt to climate change, and ultimately, based on the forgoing, as the name of the publication suggests, a road map for implementing the multilateral system in India

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Not AvailableThe development of CRISPR–Cas systems has sparked a genome editing revolution in plant genetics and breeding. These sequence-specific RNA-guided nucleases can induce DNA double-stranded breaks, resulting in mutations by imprecise non-homologous end joining (NHEJ) repair or precise DNA sequence replacement by homology-directed repair (HDR). However, HDR is highly inefficient in many plant species, which has greatly limited precise genome editing in plants. To fill the vital gap in precision editing, base editing and prime editing technologies have recently been developed and demonstrated in numerous plant species. These technologies, which are mainly based on Cas9 nickases, can introduce precise changes into the target genome at a single-base resolution. This Review provides a timely overview of the current status of base editors and prime editors in plants, covering both technological developments and biological applications.Not Availabl

Agricultural biotechnology for crop improvement in a variable climate: hope or hype?. Review

Developing crops that are better adapted to abiotic stresses is important for food production in many parts of the world today. Anticipated changes in climate and its variability, particularly extreme temperatures and changes in rainfall, are expected to make crop improvement even more crucial for food production. Here, we review two key biotechnology approaches, molecular breeding and genetic engineering, and their integration with conventional breeding to develop crops that are more tolerant of abiotic stresses. In addition to a multidisciplinary approach, we also examine some constraints that need to be overcome to realize the full potential of agricultural biotechnology for sustainable crop production to meet the demands of a projected world population of nine billion in 2050

Transcriptional Regulatory Network Analysis of MYB Transcription Factor Family Genes in Rice

MYB transcription factor (TF) is one of the largest TF families and regulates defense responses to various stresses, hormone signaling as well as many metabolic and developmental processes in plants. Understanding these regulatory hierarchies of gene expression networks in response to developmental and environmental cues is a major challenge due to the complex interactions between the genetic elements. Correlation analyses are useful to unravel co-regulated gene pairs governing biological process as well as identification of new candidate hub genes in response to these complex processes. High throughput expression profiling data are highly useful for construction of co-expression networks. In the present study, we utilized transcriptome data for comprehensive regulatory network studies of MYB TFs by top down and guide gene approaches. More than 50% of OsMYBs were strongly correlated under fifty experimental conditions with 51 hub genes via top down approach. Further, clusters were identified using Markov Clustering (MCL). To maximize the clustering performance, parameter evaluation of the MCL inflation score (I) was performed in terms of enriched GO categories by measuring F-score. Comparison of co-expressed cluster and clads analyzed from phylogenetic analysis signifies their evolutionarily conserved co-regulatory role. We utilized compendium of known interaction and biological role with Gene Ontology enrichment analysis to hypothesize function of coexpressed OsMYBs. In the other part, the transcriptional regulatory network analysis by guide gene approach revealed 40 putative targets of 26 OsMYB TF hubs with high correlation value utilizing 815 microarray data. The putative targets with MYB-binding cis-elements enrichment in their promoter region, functional co-occurrence as well as nuclear localization supports our finding. Specially, enrichment of MYB binding regions involved in drought-inducibility implying their regulatory role in drought response in rice. Thus, the co-regulatory network analysis facilitated the identification of complex OsMYB regulatory networks, and candidate target regulon genes of selected guide MYB genes. The results contribute to the candidate gene screening, and experimentally testable hypotheses for potential regulatory MYB TFs, and their targets under stress conditions