Secreted proteins of normal and myc-ras oncogene transformed rat embryo fibroblasts

Quiescent cultures of rat embryo fibroblasts synthesize and secrete several proteins in response to mitogenic stimulation. Two of these proteins have been characterized in this study and the effect of oncogenic transformation on these proteins was monitored. A serum induced 48,000 protein was shown to be related to plasminogen activator inhibitor while another serum-induced protein of Mr 45,000 was found to be an inhibitor of DNA synthesis. Transformation of rat embryo fibroblasts with oncogenesmyc andras resulted in drastic reduction in the level of these proteins. The reduced levels of protease inhibitor may be responsible for the loss of anchorage dependence of the transformed cells. The DNA synthesis inhibitor protein may act as a negative growth regulator and reduced levels of this protein in myc-ras transformed cells may accelerate the proliferation of these cells

Crop science experiments designed to inform crop modeling

Crop growth simulation models are a useful tool to assess the impact of environment, crop management, genetics and breeding strategies, as well as climate change and variability on growth and yield. Any crop science experiment that measures key physiological processes, tests these productive processes, their interaction with other processes, environment, and intra- and inter-specific variation, is valuable to inform and refine crop simulation models. This paper focuses on crop science experiments in three key areas—crop development, seed or fruit-set at high temperature, and water use—illustrating some of the experiments used to understand key processes and, equally importantly, quantify these processes for crop models in a robust and repeatable manner. One particularly useful experimental method for determining stages of development responsive to photoperiod and temperature (the main drivers of ontogenic development), and sensitive to abiotic stresses such as temperature extremes and water deficit, is transfer experiments between different environments or treatments. Once sensitive stages are defined, then responses and genotypic differences can be accurately quantified. Understanding and modeling transpiration, and particularly genotypic differences in processes affecting transpiration is also key process for crop modeling. Experiments to determine genotypic differences in soil water availability thresholds that control when transpiration is reduced, relations between transpiration and vapor pressure deficit (VPD), and patterns of soil water uptake are also described along with new insights from this work. One of the biggest constraints to improving models with crop science experiments—and exploiting advances in genomics—is the limited capacity to phenotype traits and physiological mechanisms. Most crop science experiments have quantified responses in only a limited number of genotypes and the diversity of genotypic responses is not well represented. Today there is an increased demand for good quality phenotyping which can serve both genomics and modeling, and there is an urgent need to re-invest in crop physiology for high quality phenotyping

Green revolution to genome revolution: driving better resilient crops against environmental instability

Crop improvement programmes began with traditional breeding practices since the inception of agriculture. Farmers and plant breeders continue to use these strategies for crop improvement due to their broad application in modifying crop genetic compositions. Nonetheless, conventional breeding has significant downsides in regard to effort and time. Crop productivity seems to be hitting a plateau as a consequence of environmental issues and the scarcity of agricultural land. Therefore, continuous pursuit of advancement in crop improvement is essential. Recent technical innovations have resulted in a revolutionary shift in the pattern of breeding methods, leaning further towards molecular approaches. Among the promising approaches, marker-assisted selection, QTL mapping, omics-assisted breeding, genome-wide association studies and genome editing have lately gained prominence. Several governments have progressively relaxed their restrictions relating to genome editing. The present review highlights the evolutionary and revolutionary approaches that have been utilized for crop improvement in a bid to produce climate-resilient crops observing the consequence of climate change. Additionally, it will contribute to the comprehension of plant breeding succession so far. Investing in advanced sequencing technologies and bioinformatics will deepen our understanding of genetic variations and their functional implications, contributing to breakthroughs in crop improvement and biodiversity conservation

How rising temperatures would be detrimental for cool and warm-season food legumes

Rising temperatures are a major concern for the productivity of food legumes, grown in winter as well as summer-season, especially in tropical and sub-tropical regions. Our studies have indicated marked damage to the reproductive stage, resulting in reduction in pod set and seed yield of chickpea, lentil (cool-season legumes) and mungbean (warm-season legume) under high temperatures. Studies done in controlled and outdoor environments (late sowing) revealed that temperatures >35/20°C (as day and night) were highly detrimental for winter-season legumes; while >38/25°C markedly affected the summer-season legumes (mungbean). Urdbean, (a summer season legume), was found to be relatively more tolerant. The degree of damage varies depending upon the duration, timing and severity of stress. Among the reproductive components, pollen grains were more sensitive, became deformed and showed reduction in pollen viability, reduced germination and pollen tube growth. Stigma receptivity and ovule viability were also inhibited, which affected the pollen germination on stigma surface and restricted tube growth through style, and impaired fertilization to cause flower abortion. Assessment of the physiology of leaves, anthers and styles indicated decrease in sucrose production in all these organs due to inhibition of enzymes, which possibly affected the structural and functional aspects of the pollen grains and tube growth through style. Seed filling is another stage which becomes impaired as a result of inactivation of enzymes related to sucrose production, causing inhibition in sucrose translocation into seeds. Additionally, the composition of the seeds was adversely affected, resulting in small size and poor quality of seeds. The data related to these processes would be presented. Genetic variation for heat tolerance exists in our target legume crops, which needs further probing and use of heat tolerant germplasm in breeding programs. Screening for high temperature tolerance has led to identification of few heat-tolerant genotypes, which are able to maintain their gamete function at high temperature, unlike the sensitive genotypes. Future studies should focus on high throughput phenotyping techniques and/or physiological, biochemical or genetic markers that control the reproductive function. Information about the effects of heat stress on reproductive biology and seed filling events of chickpea, lentil and mungbean will be discussed

Drought or/and Heat-Stress Effects on Seed Filling in Food Crops: Impacts on Functional Biochemistry, Seed Yields, and Nutritional Quality

Drought (water deficits) and heat (high temperatures) stress are the prime abiotic constraints, under the current and climate change scenario in future. Any further increase in the occurrence, and extremity of these stresses, either individually or in combination, would severely reduce the crop productivity and food security, globally. Although, they obstruct productivity at all crop growth stages, the extent of damage at reproductive phase of crop growth, mainly the seed filling phase, is critical and causes considerable yield losses. Drought and heat stress substantially affect the seed yields by reducing seed size and number, eventually affecting the commercial trait ‘100 seed weight’ and seed quality. Seed filling is influenced by various metabolic processes occurring in the leaves, especially production and translocation of photoassimilates, importing precursors for biosynthesis of seed reserves, minerals and other functional constituents. These processes are highly sensitive to drought and heat, due to involvement of array of diverse enzymes and transporters, located in the leaves and seeds. We highlight here the findings in various food crops showing how their seed composition is drastically impacted at various cellular levels due to drought and heat stresses, applied separately, or in combination. The combined stresses are extremely detrimental for seed yield and its quality, and thus need more attention. Understanding the precise target sites regulating seed filling events in leaves and seeds, and how they are affected by abiotic stresses, is imperative to enhance the seed quality. It is vital to know the physiological, biochemical and genetic mechanisms, which govern the various seed filling events under stress environments, to devise strategies to improve stress tolerance. Converging modern advances in physiology, biochemistry and biotechnology, especially the “omics” technologies might provide a strong impetus to research on this aspect. Such application, along with effective agronomic management system would pave the way in developing crop genotypes/varieties with improved productivity under drought and/or heat stresses

Corn Tiller Yield Contributions are Dependent on Environment: A 17 Site-Year Kansas Study

Historic breeding efforts in corn (Zea mays L.) have resulted in uniform, single-stalked phenotypes with limited potential for environmental plasticity. Therefore, plant density is a critical yield component for corn, as corn is unable to successfully compensate for a deficit of plants. Other grass crop species can overcome plant density deficits via vegetative branching (tillering), but this trait is historically undesirable in corn. Improving corn flexibility across plant densities has potential benefits, particularly considering diverse yield environments and seasonal weather uncertainties due to climate change. The present study evaluated tiller presence with two hybrids in a range of plant densities across the state of Kansas to identify yield impacts and potential usefulness of this plasticity trait in corn. Tiller presence was identified as neutral or additive to final yields, but fine-tuning plant density was confirmed as key to maximizing grain yields. Tillers have potential to stabilize yields across plant densities in productive environments. This capability may offer a source of production stability for growers when deficits develop in plant density after planting

Studies on exhaust emissions in semi-adiabatic compression ignition engine with alternate fuels

249-255Alcohols (ethanol and methanol) and a few non-edible vegetable oils are showing a great potential for replacing conventional diesel fuels quite effectively. The low heat rejection semi-adiabatic compression ignition (C.I.) engines are gaining prominence for adopting these alternate fuels. The major pollutants of the exhaust emissions of  C.I. engines are oxides of nitrogen (NOx) and black smoke. When alcohols are used as alternate fuels, the pollutants have to be checked specifically for aldehydes which are carcinogenic in nature. The pollution levels of black smoke, NOx and aldehydes emitted through exhaust of engine are reported here on both conventional and insulated versions of C. I. engines with different proportions of ethanol-diesel and methanol-diesel mixtures. The non-edible vegetable oils crude, and esterified jatropha and pongamia oils are used for total replacement of diesel fuel on both configurations of the engine. The NOx and smoke levels have been found to be lower with both ethanol and methanol induction with both conventional and insulated versions of the engine in comparison to pure diesel operation. Also, production of aldehydes in the form of formaldehyde has been found to increase with both ethanol and methanol operations. However, the insulated version of the engine with ethanol operation helps in reducing formaldehyde emissions of the engine. With the non-edible vegetable oils, generation of smoke is drastically increased in comparison to pure diesel operation. However, with preheating of vegetable oil and increased injection pressure, the smoke levels get reduced and NOx levels increase marginally