Natural systems, human health, and agricultural production have badly affected by devastating environmental changes. With the rapid increase in the world’s population, there is a corresponding increase in food demand.
By Rafia Naveed
Water availability, air pollution, and soil fertility have a large impact on agriculture productivity. With abrupt changes in environmental conditions, the harsh impacts on plant productivity are progressing in great intensities. Because of the continuous deforestation and excessive utilization of fossil fuels, the concentration of CO2 has escalated from 280 µmol−1 to 400 µmol−1 in the atmosphere. CO2 concentration will elevate two-fold according to a prediction, i.e., up to 800 µmol−1 at the end of this century. The number of stress spells, their impact on daily life, and damage to agricultural crops estimate the effects of climate change and environmental variation. In developing countries, agricultural yield predominantly suffers due to adverse environmental conditions. Therefore, high temperature and excess of CO2 accumulation forced scientists to devise new strategies to cope with less predictable challenges. Plant growth and yield are greatly inﬂuenced by abiotic stresses. Under natural climate conditions, plants often experience numerous stresses like waterlogging, drought, heat, cold, and salinity. The abiotic factors also include UV-B, light intensities, ﬂooding, gas emissions, and physical and chemical factors which induce more stresses. Crop adaptability has suffered not only as a result of temperature variations, but also because of rainfall. Currently, the main task is lessening the pressure on food security. This review emphasizes the inﬂuence of weather variations on crop production and strategies to cope with extreme environmental conditions. Some recent genetically engineered approaches develop transgenic plants against abiotic stresses.
Plant Yield and Climate Change
Climate change affects crop production by means of direct, indirect, and socio-economic effects. Furthermore, climate change (drought, ﬂood, high temperature, storm etc.) events increase dramatically as reported by Food and Agriculture Organization (FAO).
The outcomes of abiotic stresses on crop yield are hard to calculate accurately. Abiotic stresses have a substantial influence on crop production depending upon the extent of damage to the total area under cultivation. In future, the productivity of the major crops will drop in many countries due to global warming, water shortage and other environmental impacts.
Due to climate change, water deﬁcit and temperature extremes inﬂuence the reproductive phase of plant growth. Water stress in cereals badly affect the ﬂower initiation and inﬂorescence. Similarly, if the temperature increases about 30◦C during ﬂoret development it can cause sterility in cereals. Drought stress inﬂuences wheat during all developmental stages, but grain formation and the reproductive stage are the most critical ones. Wheat yield was decreased from 1% to 30% during the mild drought stress at post-anthesis. While this reduction increased up to 92% in case of prolonged mild drought stress at ﬂowering and grain formation. Drought stress has greatly reduced the yield of important grain legumes. In temperate regions and humid grassland zones, a slight elevation in temperature may raise the pasture productivity. In the case of arid and semi-arid regions, it may cause a reduction in livestock growth and enhance their death rates. The extensive rate of evapotranspiration and less moisture in the soil are predicted in drier regions by various climate models. Consequently, due to climate changes, many regions of cultivated land may become unsuitable for cultivation.
Approaches to Combat Climate Changes
- Plant breeding shows dynamic techniques in crop development and betterment. It gives a way to potentially guarantee food security and safety under harsh weather variations. It helps plants escape from various stresses through a crucial phase of plant growth by developing stress resistant cultivars
- Genome wide association studies (GWAS) is a powerful tool for understanding the complete set of genetic variants in different crop cultivars. It helps to recognize allelic variant linked with any speciﬁc trait. GWAS generally highlight linkage among SNPs and traits and based on GWAS design, genotyping tools, statistical models for examination, and results interpretation.
- Genomic selection (GS) is the exciting tool to revolutionize the crop improvement by using high-throughput phenotyping and marker densities to screen the elite germ plasm, improving the polygenic traits and economical breeding line development.
- Biotechnology is an inﬂuential approach for genetic manipulation of the genome for the betterment of human beings. The genetic modiﬁcation through biotechnology is a powerful strategy. Encouraging data is collected from genetics which exploit signiﬁcantly to various biotic and abiotic stresses such as salinity, drought, heat, and cold. Identiﬁcation of stress-responsive TFs are powerful ﬁndings to develop stress-resistant crop cultivars.
- CRISPR/Cas9 is a modern genome editing strategy based on the prokaryotic defense mechanism triggered by type II RNA organization that offers protection to prokaryotes against attacking viruses. CRISPR-Cas9 assembly has modernized Genome editing by producing candidate gene mutants and knock down single nucleotides in a genome. CRISPR-based strategies have tremendously exploited in plant genome. Moreover, it has great potential to aid crop breeding to establish high yielding and stress-resistant varieties. CRISPR/Cas9 tool is converting into a environmentally friendly technique for the establishment of genome edited non-transgenic plants. Its purpose is to tackle environmental extremes and guarantee food security.