Abiotic stresses are the major environmental factors that play a significant role in decreasing plant yield and production potential by influencing physiological, biochemical, and molecular ...processes. Abiotic stresses and global population growth have prompted scientists to use beneficial strategies to ensure food security. The use of organic compounds to improve tolerance to abiotic stresses has been considered for many years. For example, the application of potential external osmotic protective compounds such as proline is one of the approaches to counteract the adverse effects of abiotic stresses on plants. Proline level increases in plants in response to environmental stress. Proline accumulation is not just a signal of tension. Rather, according to research discussed in this article, this biomolecule improves plant resistance to abiotic stress by rising photosynthesis, enzymatic and non-enzymatic antioxidant activity, regulating osmolyte concentration, and sodium and potassium homeostasis. In this review, we discuss the biosynthesis, sensing, signaling, and transport of proline and its role in the development of various plant tissues, including seeds, floral components, and vegetative tissues. Further, the impacts of exogenous proline utilization under various non-living stresses such as drought, salinity, high and low temperatures, and heavy metals have been extensively studied. Numerous various studies have shown that exogenous proline can improve plant growth, yield, and stress tolerance under adverse environmental factors.
•Mixed convection of a nanofluid inside vertical annuli was studied theoretically.•Flow has been assumed to be hydrodynamically and thermally fully developed.•Buoyancy has negative effects on the ...performance.•Induced slippage at the surface due to the nanoparticles enhance the performance.•Velocity profile becomes more uniform as the slip parameter increases.
This paper deals with the mixed convective heat transfer of nanofluids through a concentric vertical annulus. Because of the non-adherence of the fluid–solid interface in the presence of nanoparticle migrations, known as slip condition, the Navier’s slip boundary condition was considered at the pipe walls. The employed model for nanofluid includes the modified two-component four-equation non-homogeneous equilibrium model that fully accounts for the effects of nanoparticles volume fraction distribution. Assuming the fully developed flow and heat transfer, the basic partial differential equations including continuity, momentum, and energy equations have been reduced to two-point ordinary boundary value differential equations and solved numerically. Two cases including constant heat flux at the outer wall and insulated inner wall (Case A) and constant heat flux at the inner wall with insulated outer wall (Case B) have been considered. Results indicate that the buoyancy has negative effects on the efficiency of the system; however, slip velocity at the surface enhances both the heat transfer rate and the efficiency.
Global food security requires food production to be increased in the future decades. Agro-Ecological Zones (AEZ) methodology is a successful approach used in land evaluation studies to support ...sustainable agricultural development. This approach can facilitate finding suitable areas for wheat production on a global scale. This study was conducted based on a climate zone map, soil data, wheat cultivation area, yield, and production under irrigated and rainfed conditions, worldwide. The results for irrigated wheat indicated that there is an area of 59.5 Mha with an average yield of 4.02 t/ha which leads to the production of about 239.6 Mt of grain yield. Furthermore, climate zones (CZs) of 8002, 5203, 5302, 5403, and 8102 have the highest wheat production with an average of 20.7, 14.2, 13.3, 11.8, 11.5 Mt, respectively. The highest amount of irrigated wheat production has been achieved in soil type code 17 (Loam LF120), which has a cultivation area of around 23.6 Mha and a production of about 106.8 Mt. Rainfed wheat production is 410 Mt, and the cultivation area is 160.2 Mha. The highest rainfed wheat production with an average of 17 Mt was related to the 3702 CZ, followed by the other CZs (3802, 1303, 1203, 3602, 4602, etc.). The soil codes 11 (Loam HF120), 10 (Loam HF180), and 14 (Loam MF120) showed the highest rainfed wheat production. The findings of this study can be useful for agricultural scientists, authorities, and decision-makers around the world to find suitable lands to expand wheat cultivation and also to find new locations for increasing global wheat production to feed the increasing population in the world.
The quality of crop establishment is affected by several biotic and abiotic factors. The adverse impact of these factors can be mitigated through crop management practices. Development of practical ...management solutions may help farmers to reduce their production costs and thus increase yield. Here, we report practical and sustainable methods that aim at improving the establishment quality and yield of three key cereal crops viz. maize, rice and wheat, particularly suitable for drought-prone regions. We found that some new methods including printed sowing, variable-rate seeding, night-time sowing as well as other relatively old methods such as bed- and raised-bed sowing, mulching, incorporation of organic matters into the seedbed etc. allow to improve crop establishment and yield while increasing water use efficiency and reducing greenhouse gas emissions. However, there is no a ‘one-size-fits-all’ method to improve cereal crop establishment and that the potential adoption of such methods by farmers may be affected by a number of factors, including the farm size and the crop type. We highlight that the methods presented herein have been successfully tested only for maize, rice and wheat and across limited pedo-climatic conditions. Consequently, there is a knowledge gap about the potential of these methods to implement for a broader range of crops and cropping systems across drought-prone regions of the world. This will finally improve our understanding of the overall effectiveness of these methods in fostering crop establishment, early stand development and yield.
Maize establishment under conventional tillage system. Display omitted
•Seedbed preparation and management methods affect seedbed moisture.•Seedbed moisture in turn affects crop establishment and yield.•Both relatively old and new sowing methods are reviewed.•Some seedbed preparation and management methods improve water use efficiency.•These methods need to be tested for a broader range of crops.
The Data and Resource Center (DRC) of the NIH-funded SPARC program is developing databases, connectivity maps, and simulation tools for the mammalian autonomic nervous system. The experimental data ...and mathematical models supplied to the DRC by the SPARC consortium are curated, annotated and semantically linked via a single knowledgebase. A data portal has been developed that allows discovery of data and models both via semantic search and via an interface that includes Google Map-like 2D flatmaps for displaying connectivity, and 3D anatomical organ scaffolds that provide a common coordinate framework for cross-species comparisons. We discuss examples that illustrate the data pipeline, which includes data upload, curation, segmentation (for image data), registration against the flatmaps and scaffolds, and finally display via the web portal, including the link to freely available online computational facilities that will enable neuromodulation hypotheses to be investigated by the autonomic neuroscience community and device manufacturers.
Iran's population is predicted to reach 103 million by 2050. Food for this population and environmental protection are challenging, because Iran's land and water resources have crossed safety ...boundaries.
This study analyzes the impact of current diets and proposed diets on water consumption, land use, and inputs, such as nutrients, energy, and greenhouse gas emissions.
The proposed diets were compared to the current diet and the Ministry of Health's recommended diets. The proposed diets were designed to reduce animal product consumption and place more demand for plant products. A plant-based diet was developed and compared with other diets, and all the proposed diets were designed in accordance with WHO recommendations.
In comparison with the current diet, the Ministry of Health's optimal diet requires 10 % more primary resources, increases greenhouse gas emissions by 10 %, and increases the cost of purchasing items from retailers by 13 %. Moreover, plant-based diets require about 30 % of blue water resources based on our designed plan. The required agricultural production for this plan requires 8–12 % less fertilizer and 15 % less energy, thus reducing greenhouse gas emissions by 10–14 %. These diets also cost 20–24 % less; however, adopting and implementing sustainable plant-based diets requires better education.
It is recommended that reevaluation of the Ministry of Health's current optimal diet is essential. The results of the current study, which introduces plant-based modified diets, may be able to provide alternative diet recommendations for Iranians.
Germination timing is an important determinant of survival and niche breadth of plants. The annual plant Nigella sativa occurs in diverse environments along a steep temperature gradient and thus is a ...suitable model for the study of germination behavior in response to temperature. We used a modeling approach to compare the germination thermal niche of seeds of nine populations of N. sativa produced in a common garden. Germination time courses were obtained by a newly developed process‐based model, and thermal niche was visualized by plotting germination breadth as a function of after‐ripening time. Seeds were sampled five times: immature (2 weeks before maturity), mature, and afterripened for 1, 2, and 5 months. Immature and mature seeds had a greater depth of dormancy than afterripened seeds, as estimated by lower values of high‐limit temperatures (Th). Afterripening increased germination percentage, synchrony, and thermal niche breadth of all nine populations. The highest asynchrony was for immature and mature seeds, and afterripening enhanced synchrony. Based on the new graphical method, N. sativa has Type 1 nondeep physiological dormancy, and thus, the germination niche is narrow at seed maturity, leading to a delayed germination strategy that is highly dependent on thermal time accumulated during afterripening. Our findings show that there is considerable variation in the germination thermal niche among populations. Temperature regimes in the natural habitats of N. sativa have played a significant role in shaping variation in thermal niche breadth for seed germination of this annual species. The models used in our study precisely predict germination behavior and thermal niche under different environmental conditions. The germination synchrony model also can estimate germination pattern and degree of dormancy during the year, suggesting a useful method for quantification of germination strategies.
We used a modeling approach to compare the germination thermal niche of seeds of nine populations of Nigella sativa produced in a common garden. Germination time courses were obtained by a newly developed process‐based model, and thermal niche was simulated via a new graphical method.
As an abiotic stress, adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination. Using a factorial experiment, we examined the ...effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures. Each of the rice genotypes (Hashemi, Sadry-domsefid, IRON-70-7053-7 and NORIN-22) was primed with hydro-hardening, KCl, CaCl2 and ascorbic acid (AsA) and without a priming agent as a control at low (15 ºC), optimum (25 ºC) and high (35 ºC) germination temperatures. The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents, especially under the low germination temperature. At 15 ºC, seed priming with AsA was found to be the best agent for the activities of amylase, α-amylase, catalase (CAT), peroxidase (POX), ascorbate peroxidase (APOX) and superoxide dismutase (SOD) as well as the content of soluble sugars in the NORIN-22 genotype, and for protease activity and soluble protein content in the IRON-70-7053-7 genotype. SOD at the low germination temperature and CAT, POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length, vigor index, normal seedling rate and germination rate. Under the priming agents, the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes, and at the high germination temperature under KCl priming in the Hashemi genotype.
Numerous reports find that Cd induces formation of reactive oxygen species (ROS) in plants. However, a general ROS pool is usually studied, without distinction of their production site. In the ...present study, we applied a mitochondria-specific antioxidant, MitoTEMPO, to elucidate the role of mitochondria-derived ROS in the response of soybean seedlings to short-term (48 h) Cd stress. The obtained results showed that Cd caused a reduction in root length and fresh weight and increase in the level of superoxide anion, hydrogen peroxide, markers of lipid peroxidation (thiobarbituric reactive substances, TBARS) and markers of RNA oxidation (8-hydroxyguanosine, 8-OHG) in seedling roots. Application of MitoTEMPO affected Cd uptake in a dose-dependent manner and diminished the Cd-dependent induction of superoxide anion and lipid peroxidation.
Herbicide resistance can affect seed germination and the optimal conditions required for seed germination, which in turn may impose a fitness cost in resistant populations. Winter wild oat Avena ...sterilis L. ssp. ludoviciana (Durieu) Gillet and Magne is a serious weed in cereal fields. In this study, the molecular basis of resistance to an ACCase herbicide, clodinafop-propargyl, in four A. ludoviciana biotypes was assessed. Germination differences between susceptible (S) and ACCase-resistant biotypes (WR1, WR2, WR3, WR4) and the effect of Isoleucine-1781-Leucine mutation on germination were also investigated through germination models. The results indicated that WR1 and WR4 were very highly resistant (RI > 214.22) to clodinafop-propargyl-contained Isoleucine to Leucine amino acid substitution. However, Isoleucine-1781-Leucine mutation was not detected in other very highly resistant biotypes. Germination studies indicated that resistant biotypes (in particular WR1 and WR4) had higher base water potentials than the susceptible one. This shows that resistant biotypes need more soil water to initiate their germination. However, the hydrotime constant for germination was higher in resistant biotypes than in the susceptible one in most cases, showing faster germination in susceptible biotypes. ACCase-resistant biotypes containing the Isoleucine-1781-Leucine mutation had lower seed weight but used more seed reserve to produce seedlings. Hence, integrated management practices such as stale seedbed and implementing it at the right time could be used to take advantage of the differential soil water requirement and relatively late germination characteristics of ACCase-resistant biotypes.
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