A minimal peach type II chlorophyll a/b-binding protein promoter retains tissue-specificity and light regulation in tomato

<p>Abstract</p> <p>Background</p> <p>Promoters with tissue-specificity are desirable to drive expression of transgenes in crops to avoid accumulation of foreign proteins in edible tissues/organs. Several photosynthetic promoters have been shown to be strong regulators of expression of transgenes in light-responsive tissues and would be good candidates for leaf and immature fruit tissue-specificity, if expression in the mature fruit were minimized.</p> <p>Results</p> <p>A minimal peach chlorophyll <it>a/b</it>-binding protein gene (<it>Lhcb2*Pp1</it>) promoter (Cab19) was isolated and fused to an <it>uid</it>A (β-glucuronidase [GUS]) gene containing the PIV2 intron. A control vector carrying an enhanced <it>mas</it>35S CaMV promoter fused to <it>uid</it>A was also constructed. Two different orientations of the Cab19::GUS fusion relative to the left T-DNA border of the binary vector were transformed into tomato. Ten independent regenerants of each construct and an untransformed control line were assessed both qualitatively and quantitatively for GUS expression in leaves, fruit and flowers, and quantitatively in roots.</p> <p>Conclusion</p> <p>The minimal CAB19 promoter conferred GUS activity primarily in leaves and green fruit, as well as in response to light. GUS activity in the leaves of both Cab19 constructs averaged about 2/3 that observed with <it>mas</it>35S::GUS controls. Surprisingly, GUS activity in transgenic green fruit was considerably higher than leaves for all promoter constructs; however, in red, ripe fruit activities were much lower for the Cab19 promoter constructs than the <it>mas</it>35S::GUS. Although GUS activity was readily detectable in flowers and roots of <it>mas</it>35S::GUStransgenic plants, little activity was observed in plants carrying the Cab19 promoter constructs. In addition, the light-inducibility of the Cab19::GUS constructs indicated that all the requisite <it>cis</it>-elements for light responsiveness were contained on the Cab19 fragment. The minimal Cab19 promoter retains both tissue-specificity and light regulation and can be used to drive expression of foreign genes with minimal activity in mature, edible fruit.</p

Nitrogen partitioning and remobilization in relation to leaf senescence, grain yield and protein concentration in Indian wheat cultivars

© 2020 The Authors Nitrogen (N) fertilizer represents a significant cost for the grower and may also have environmental impacts through nitrate leaching and N2O (a greenhouse gas) emissions associated with denitrification. The objectives of this study were to quantify the genetic variability in N partitioning and N remobilization in Indian spring wheat cultivars and identify traits for improved grain yield and grain protein content for application in breeding N-efficient cultivars. Twenty-eight bread wheat cultivars and two durum wheat cultivars were tested in field experiments in two years in Maharashtra, India. Growth analysis was conducted at anthesis and harvest to assess above-ground dry matter (DM) and dry matter and N partitioning. Flag-leaf photosynthesis rate (Amax), flag-leaf senescence rate and canopy normalized difference vegetation index (NDVI) were also assessed. Significant N × genotype level interaction was observed for grain yield and N-use efficiency. There was a positive linear association between post-anthesis flag-leaf Amax and grain yield amongst the 30 genotypes under high N (HN) conditions. Flag-leaf Amax was positively associated with N uptake at anthesis (AGNA). Under both HN and low N (LN) conditions, higher N uptake at anthesis was associated with delayed onset of flag-leaf senescence and higher grain yield. Under N limitation, there was a genetic negative correlation between grain yield and grain protein concentration. Deviation from this negative relationship (grain protein deviation or GPD) was related to genotypic differences in post-anthesis N uptake. It is concluded that N uptake at anthesis was an important determinant of flag-leaf photosynthesis rate and grain yield under high N conditions; while post-anthesis N uptake was an important determinant of GPD of wheat grown under low to moderate N conditions in India

Stress Induced Lipids Accumulation in Naviculoid Marine Diatoms for Bioenergy Application

Microalgae are expected to play promising role in the production of biofuel in current research. Two of marine diatoms, Navicula sp. and Amphora sp. were isolated and their growth rate was also studied. Total lipid content was analyzed in stationary growth state under normal conditions. By the two stage process, both the diatoms were subjected to nitrogen and silicon undersupplied for five days and the total lipid accumulation in the diatoms were found to be increased during nutrient deficiency period. The nutrient deficit conditions prone to increased total lipid content and also altered the fatty acid profile in diatom. The total lipid content of Navicula sp. and Amphora sp. were found to be 34.93% DCW and 41.10% DCW under normal conditions and in nitrogen deficiency conditions it has been increased to 60.71% DCW and 64.72% DCW respectively. The major fatty acids were found to be cis-10-Heptadecanoic acid (27.54%) and stearic acid (24.57%). The level of saturated and monounsaturated fatty acids were found to be high in both the diatoms. The presence of low level of polyunsaturated fatty acids indicated that these two organisms could find future application in bioenergy production

Genetic variation in N-use efficiency and associated traits in Indian wheat cultivars

Nitrogen (N) fertilizer represents a significant cost for the grower and may also have environmental impacts through nitrate leaching and N⁠2O (a greenhouse gas) emissions associated with denitrification. The objectives of this study were to quantify the genetic variability in N-use efficiency (NUE) in Indian spring wheat cultivars and identify traits for improved NUE for application in breeding. Twenty eight bread wheat cultivars and two durum wheat cultivars were tested in field experiments in two years in Maharashtra, India. Detailed growth analysis was conducted at anthesis and harvest including dry matter (DM) and N partitioning. Senescence of the flag leaf was assessed from a visual score every 3–4 days from anthesis to complete flag-leaf senescence and fitted against thermal time to estimate the onset and end of post-anthesis senescence. Grain yield (GY) was reduced under low N (LN) by an average of 1.59t ha⁠−1 (−28%). Significant N×genotype level interaction was observed for grain yield and NUE. Above-ground N uptake at harvest was reduced from 162kg N ha⁠−1 under high N (HN) to 85kg N ha −1 under low N (LN) conditions, while N-utilization efficiency (grain DM yield per unit crop N uptake at harvest; NUtE) increased from 32.7 to 44.6kg DM kg −1 N. Genetic variation in GY under LN related mainly to variation in N uptake at harvest rather than NUtE; and the N×genotype effect for GY was mainly explained by the interaction for N uptake at harvest. Averaging across years, the linear regression of onset of flag-leaf senescence on GY amongst cultivars was significant under both HN (R2 0.16. p<0.05) and LN (R2 0.21, p<0.05) conditions. Onset of flag-leaf senescence was positively associated with N uptake at anthesis under HN (R2 0.34, p<0.001) and LN (R2 0.22, p<0.01) conditions. Flag-leaf senescence timing was not associated with post-anthesis N uptake. It is concluded that increased N accumulation at anthesis was correlated with flag-leaf senescence timing and that N accumulation at anthesis is an important trait for enhancing grain yield and NUE of wheat grown under low to moderate N supply in India

Facile and Novel Strategy for Methods of Extraction of Biofuel Grade Lipids from Microalgae- an Experimental Report

The structural features of microalgal cell make it too difficult to extract the total lipid content of the cell as such. Thus, the cell disruption before lipid extraction becomes mandatory and has to be cost-effective. In the present study various methods and combination of few methods were adopted for effective extraction in order to choose the most effective cell disruption method for the complete extraction of lipids from a selected indigenous freshwater isolate, Scenedesmus sp. NTEB03. Interestingly, we found that grinding and bead-beating method showed two fold increased lipid productivity (23.2%) than the other methods tested. Biomass and lipid productivity of Scenedesmus sp., was found to be 0.0418 g L-1 d-1 and 4.3 mg L-1 d-1 respectively. Fatty acid profiles revealed that oleic (C18:1) and linoleic acid (C18:2) content being higher in the lipids, which are most appropriate for the biodiesel production. A novel strategy for most effective, simple method for cell disruption in Scenedesmus sp., was grinding/bead-beating, which is the most suitable method for complete extraction of biofuel grade lipids

NGAL is downregulated in oral squamous cell carcinoma and leads to increased survival, proliferation, migration and chemoresistance

Oral cancer is a major public health burden worldwide. The lack of biomarkers for early diagnosis has increased the difficulty in managing this disease. Recent studies have reported that neutrophil gelatinase-associated lipocalin (NGAL), a secreted glycoprotein, is upregulated in various tumors. In our study, we found that NGAL was significantly downregulated in primary malignant and metastatic tissues of oral cancer in comparison to normal tissues. The downregulation of NGAL was strongly correlated with both degree of differentiation and stage (I–IV); it can also serve as a prognostic biomarker for oral cancer. Additionally, tobacco carcinogens were found to be involved in the downregulation of NGAL. Mechanistic studies revealed that knockdown of NGAL increased oral cancer cell proliferation, survival, and migration; it also induced resistance against cisplatin. Silencing of NGAL activated mammalian target of rapamycin (mTOR)signaling and reduced autophagy by the liver kinase B1 (LKB1)-activated protein kinase (AMPK)-p53-Redd1 signaling axis. Moreover, cyclin-D1, Bcl-2, and matrix metalloproteinase-9 (MMP-9) were upregulated, and caspase-9 was downregulated, suggesting that silencing of NGAL increases oral cancer cell proliferation, survival, and migration. Thus, from our study, it is evident that downregulation of NGAL activates the mTOR pathway and helps in the progression of oral cancer

Resultative Compound Verb in Modern Chinese : A Comment on Imai(1985) and Lu(1986)

<p>A. API and DMO suppresses NF-κB DNA binding ability in HCT116 cells. HCT116 cells were treated with DMO and API at indicated doses, nuclear extracts were prepared, and 20 μg of the nuclear extract protein was used for the ELISA-based DNA-binding assay *p<0.05; **p<0.005). B & C. NF-κB responsive elements linked to a luciferase reporter gene were transfected with wild-type or dominant-negative IκB and transfected cancer cells were treated at indicated doses for 6 h and luciferase activity was measured as described in Materials and Methods section. All luciferase experiments were done in triplicate and repeated twice (*p<0.05; **p<0.005). D. API abrogates constitutive IκBα phosphorylation in dose-dependent manner in HCT116 cells. HCT116 cells were treated with different concentrations of API (0, 5, 10 and 20 μM) for 6 h and cytoplasmic extract was prepared. Lysates were resolved on SDS gel and electrotransferred to a nitrocellulose membrane and probed with anti-phospho-IκBα/IκBα. The blot was washed, exposed to HRP-conjugated secondary antibodies for 1 h, and finally examined by chemiluminescence. GAPDH was used as loading control.</p