NOPR Collection:

Understanding the mode of regulation of proline biosynthesis for drought tolerance in transgenic rice overexpressing PDH47 gene

Wed, 01 Apr 2020 00:00:00 GMT

Title: Understanding the mode of regulation of proline biosynthesis for drought tolerance in transgenic rice overexpressing PDH47 gene Authors: Singha, Dhanawantari L.; Sarma, Sangeeta; Singh, Salvinder Abstract: Plants respond to drought stress by inducing proline accumulation which would promote drought tolerance. During drought, several reports described activation/overexpression of genes encoding enzymes for glutamate and ornithine-based proline biosynthesis pathways that provide tolerance to the plant. Pea DNA helicase 47 (PDH47), involves in drought stress tolerance. However, the exact mechanism for drought tolerance is not known. The present study will provide insights into how overexpression of a PDH47 in transgenic rice confers drought tolerance by further escalating the accumulation of proline. Here, the developed transgenic plants expressing PDH47 showed increased tolerance to drought with increased expression of proline biosynthesis genes. Therefore, understanding the combined regulation for expression of proline metabolism genes during drought stress in rice overexpressing drought stress-responsive DEAD-box helicase like PDH47 may result in engineering economically important crop plants for more tolerant to drought stress. Page(s): 73-81

Expression analysis of maize genes during Bipolaris maydis infection and assessing their role in disease resistance and symptom development

Wed, 01 Apr 2020 00:00:00 GMT

Title: Expression analysis of maize genes during Bipolaris maydis infection and assessing their role in disease resistance and symptom development Authors: Meshram, Shweta; Gogoi, Robin; Bashyal, Bishnu Maya; Kumar, Aundy; Mandal, Pranab Kumar; Hossain, Firoz Abstract: Bipolaris maydis causing maydis leaf blight (MLB) is an aggressive fungal pathogen of maize. The present study focused on the responses of certain defence genes in the resistant and susceptible maize inbred lines viz., SC-7 and CM 119, respectively, against MLB and symptom development in the host. Biochemical activity of the PR protein β-1, 3-glucanase and phenylalanine ammonia lyase (PAL) assay, with total chlorophyll content was recorded for both the inbred lines before and after pathogen inoculation. Gene expression was studied by quantitative polymerase chain reaction (qPCR) at different time intervals post inoculation. Differential expression pattern was observed even at the same time point in both the inbred lines. Enhanced expression of the pathogenesis related (PR) protein and phenylalanine ammonia lyase (PAL) enzyme at different time points in resistant lines indicated their association with infection stages of B. maydis and response of the resistant line against disease establishment. Down regulated gene expression of pheophytinase suggests reduced enzyme activity linked with less chlorophyll degradation in the resistant line compared to the susceptible line. This fact directly correlates with symptom development of MLB disease. The present study thus revealed that the expression of defence related genes is aligned with developmental stages of the pathogen to restrict its growth and gene expression of constitutive genes also changes differentially during the disease development in resistant and susceptible lines. Page(s): 82-93

Constitutive expression of protease inhibitor gene isolated from black gram (Vigna mungo L.) confers resistance to Spodoptera litura in transgenic tobacco plants

Wed, 01 Apr 2020 00:00:00 GMT

Title: Constitutive expression of protease inhibitor gene isolated from black gram (Vigna mungo L.) confers resistance to Spodoptera litura in transgenic tobacco plants Authors: Jagdish, Mudiyappanayar; Koundal, K R Abstract: Plant insecticidal proteins like protease inhibitors have been reported to confer insect resistance in transgenic plants. We have cloned a protease inhibitor gene of black gram (Vigna mungo L.) and developed transgenic tobacco plants expressing the protease inhibitor constitutively under the 35S promoter by Agrobacterium tumefaciens mediated genetic transformation. A full-length open reading frame (ORF) of 545 nucleotides codes for a serine protease inhibitor protein with a deduced sequence of 180 amino acids contributing to a predicted molecular mass of 20.2 kDa. The Vigna mungo protease inhibitor (VmPI) is basically a Bowman-Birk type proteinase inhibitor (BBI) of double headed type; family of plant serine protease inhibitors that block trypsin or chymotrypsin. Comparison for conserved domain in the protein by National Centre for Biotechnology Information (NCBI) conserved domain (CD) search showed that the regions from 113-168 amino acid residues have the conserved domain of which 9 residues compose reactive loops on the conserved domain of BBI. The transgenic tobacco plants developed were confirmed by Southern, northern hybridization, polymerase chain reaction (PCR) and reverse transcriptase-PCR (RT-RCR) analysis. When transgenic T₁ tobacco plants were analyzed for insecticidal bioassays, the larval growth of Spodoptera litura, the tobacco cutworm was found severely retarded as compared to their growth on control plants. Therefore, black gram protease inhibitor could be used as an alternative individually or in combination with other insecticidal genes for the development of insect-resistant transgenic crop plants. Page(s): 94-101

Assessment of phenotypic developmental traits and hybrid vigour in Arabidopsis thaliana

Wed, 01 Apr 2020 00:00:00 GMT

Title: Assessment of phenotypic developmental traits and hybrid vigour in Arabidopsis thaliana Authors: Gupta, Astha; Sawant, Samir V.; Yadav, Hemant Kumar Abstract: The Don-0 and Col-0 ecotypes of Arabidopsis thaliana showed significant phenotypic diversity for several quantitative traits. The phenotypic data taken on hybrid derived from Col-0 x Don-0 and parental lines provides the information of their continuous developmental pattern throughout the life cycle. The developmental data exhibits heterosis for most of the traits (specifically biomass related traits) due to supplementary genetic contributions of both parents. Consequently, the hybrid was found to be more vigorous in comparison to both the parents in terms of all the traits except yield trait. Moreover, higher and lower performance of hybrid causes due to constructive (hybrid vigor) and deleterious epistatic interactions of loci (necrosis: hybrid incompatibility), respectively. The present study also concluded that Don-0 is a slow growing, delayed flowering and high biomass containing ecotype. The shoot and root biomass at initial stage was found to be less in Don-0 than the Col-0 but high at maturity. The present investigation provides the preliminary information which could be utilized for future genetic studies to understand the heterotic phenomenon in Arabidospsis. Page(s): 102-112