Tuesday, 11 August 2020

Lupine Publishers | Climate change Mitigation and Adaptation through Biotechnology Approaches: A review

  Lupine Publishers | Current Investigations in Agriculture and Current Research

Abstract

Climate change associated factors including temperature increases, changes in rain fall pattern and occurrence of pest and diseases negatively influence agricultural production, productivity and quality. Climate change effects particularly in region suffer persistent soil and water resource scarcity significantly increases production risk. The effects of climate change on agriculture may depend not only on changing climate condition, but also on the ability to adapt through changes in technology and demand for food. Biotechnology positively reduced the effects of climate change by using modern biotechnology. Modern biotechnology through the use of genetically modified stress tolerant and high yielding transgenic crops also stand to significantly counteract the negative effects of climate change. Convectional biotechnology such as bio fertilizer and energy efficient farming are among reasonable options that could solve problems of climate change. Also this paper deals with the modern technology like omics, system biology and other technology has discussed to combat abiotic stress of plant. Finally, the paper highlighted the current challenges and future perspective of biotechnology for climate change adaptation and mitigation.

Keywords: Biotechnology; Climate change; Omics; System biology; Mcyo biotechnology

Introduction

CAccording to IPCC (Intergovernmental Panel on Climate Change), climate change is the mean change or variability of its properties for long period. As per report of IPCC climate change mainly caused by both anthropogenic which include change in land use by human being action and natural forces like accent of solar cycles, volcanic eruption and continental drift [1]. Climate change is one of the chief intimidations to agriculture in the vicinity of futures. Its most apparent effects would be on temperature, precipitation, insect pest and pathogen, weeds soil and water quality. It observed that agricultural activities contribute 25% green houses gas emission and major source of methane (48%) and nitrous oxide (52%) from rice fields [2]. Green house gases are element of both natural and anthropogenic which avert radiation from being to reflect into atmosphere and causing warm environment. These gases mainly emit by industry and other activities like carbon dioxide (CO2), methane (CH4), nitrous oxide, hydrofluorocarbons (HFCs) and Sulphur hexaoxide (SF6). In long run their concentration in the atmosphere increased by different activities and lets the global climate changes Kumar et al. 2015.

Adaptation to climate change can be done by reducing the vulnerability of natural and human systems [1]. Climate change mitigation is another policy retort to climate change which reduces the negative impact of climate change through involvement of human action particularly by reducing the concentration of green house gasses either by decreasing the source and increasing their sink (plants). Climate change can be mitigated by reforestation and other sink to remove concentration of CO2 from the atmosphere and shifting from biomass to renewable energy [2]. Crop yield and quality is decreased as frequent and intense precipitation events, elevated temperature, drought, and other type of damaging weather, which is making the challenge of feeding fast growing population intricate Hatfield et al. 2011. To feed the ever increasing world’s population, there must be a need to boost agricultural production.

Agricultural biotechnology involves the practical application of biological organisms, or their sub-cellular components in agriculture. The techniques currently in use include tissue culture, convectional breeding, and molecular marker assisted breeding and genetic engineering. Biotechnology is a promise way for mitigating the negative effects of climate change through reduction of green house gasses Teasury, 2009 use of bio fuels [3], carbon sequestration [4], less use of fertilizers [5], tolerance of a biotic [6] and biotic stress [7]. Under this context the present paper emphasize the intervention of biotechnology in climate change adaptation and mitigation for sustainable yield production and food security.

Role of Biotechnology for Climate Change Mitigation

Reduction GHGS emission

Agricultural practices such as use of synthetic fertilizer, cultivation rice crops, over grazing and deforestation are contributes 25% of Green houses gasses (carbon dioxide, methane and nitrous oxide) emission to atmosphere. Biotechnology is one of the most reliable answers to mitigate climate change through use energy efficient farming, carbon sequestration and reduced synthetic fertilizer usage [8]. Planting genetically modified crops has shown significant reduction in the amount of greenhouse gases emitted. This is owing to the fact that since genetically modified crops does not need as much maintenance as regular crops; farmers are not wasting as much fuel to power their equipment, resulting in a reduction of greenhouse gases emitted [9]. This reduction of greenhouse gases emitted is not a negligible reduction. The reduction of these greenhouse gas emissions in 2012 was equivalent to “removing 27 billion kg of carbon dioxide from the atmosphere or equal to removing 11.9 million cars from the road for one year” [10]. The simple yet effective implementation of genetically modified crops in farming leads farmers to expend less fuel as a result of not demanding to ride on farm equipment as long, leading to a reduction of the carbon footprint that is left behind.

Use of energy efficient farming

Now a day’s green biotechnology (the creation of more fertile and resistant plant resources by using specialized techniques) has been used in eradicating world hunger by using different technologies which enable the production of more fertile and resistant plants towards both biotic and abiotic stress (Kafarski, 2012). This technology allow farmers to use less and environmental friendly energy and fertilizer, and practice soil carbon sequestration. Production of bio fuels, both from traditional and GMO crops such as oilseed, sugarcane, rape seed and jatropha will help to reduce the adverse effects of pollution by the transport sector [8,11]. Efficient farming will therefore help in cleaning the atmosphere through plantation of perennial non edible oil-seed. Thus, directly get involved in production of bio diesel for direct use in energy sector. Then it blends along with fossil fuels, which helps to reduce the emission of carbon dioxide [12,13].

Carbon sequestration

Carbon sequestration is the uptake of carbon containing substances particularly carbon dioxide from the atmosphere. It helps to collect CO2 from the atmosphere and increase the soil organic carbon content with implication of that increased soil carbon storage mitigates climate change [14]. From this point of view carbon sequestration is one the best way to mitigate climate change impact by sequestering the ever increasing concentration of CO2 from the atmosphere. One way of increasing carbon sequestering is by conservation tillage, any tillage and planting system that covers more than 30% of the soil surface with crop residue after planting to reduce erosion by water there by enhances methane consumption and sequesters soil carbon [15].

Genetically modified crops are led to sequestration million tons of carbon dioxide from the atmosphere. One of the best examples is Roundup Ready TM which is herbicide resistant of soybean was found to sequester 63,859 million tones of CO2 in USA and Argentina [8,16]. The improvement of crops opens door for the farmers to use no till farming practice. In context of climate change mitigation (Table 1), these techniques improve soil quality and anchor carbon in the soil [17]. FAO have quantified the contribution of conservation tillage to carbon sequestration. Soil carbon sequestration for the first decade of adoption of best conservation agricultural practice was seen to decreased 1.8 tons CO2 per hectare per year, with better cycling of nutrients and avoiding nutrient losses among the key benefits to farmer FAO [18].

Table 1: Summary of carbon sequestration impact 1996-2008.

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Source: Europa bio, 2009.

Reduced use of synthetic fertilizer

Uses of synthetic fertilizer in agriculture sector have led to contaminate the environment with hazardous toxic chemicals. These synthetic fertilizers contribute for the formation as well as releases of certain green houses gasses (N2O) by bringing from the soil to surrounding atmosphere when they interact with common soil bacteria. Ammonium chloride, Ammonium sulphate, sodium nitrate, calcium nitrate are the examples of inorganic fertilizers that are responsible for the formation and releases of green house gasses [17]. Biotechnological option bids an advantage to reduce the use of synthetic fertilizer. Nitrogen fixing characteristics of Rhizobium inoculants were improved by using genetic engineering [19]. A bright prospect of non leguminous plants (rice and wheat) being enable to fix nitrogen in the soil as reported by Yan [5] and Saikia [20]. Another strategy is planting crops in the use of nitrogen more efficiently. An example of such crops is genetically modified Canola which has shown significant reduction in the amount of nitrogen fertilizer that lost into atmosphere and leached into soil and water ways, and maximizing the economies of farmers through the improved profitability [8].

Biotechnology for Crop Adaptation to Environmental Stress

The ultimate climate change effects on agriculture are reduction crop yield due to rainfall, extreme temperature, emergence of weeds, occurrence pest and disease Johnsona et al. 2007 (Table 2). One of the possible ways of adapting to such global problem is apply agricultural biotechnologies that combat the negative effects of such changes is by using genetic engineering offer new opportunities for improving stress resistance [21].

Table 2: Modern agricultural biotechnologies for climate change adaptation and mitigation.

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Source: Mtui et al. [2].

Adaptation to abiotic stresses

Climate change causes a lot of challenges in agricultural land water uses. Of these challenges, abiotic stress including like salinity, drought, extreme temperatures, and chemical toxicity have negative impact on agriculture production. Climate change creates a gigantic challenge in terms of available agricultural land and fresh water use. The agricultural sector uses about 70% of the available fresh water and this is likely to increase as temperature rises [17]. Furthermore, about 25 million acres of land is vanished each year owed to salinity caused by unsound irrigation technique [18]. It is also estimated that increased salinity in arable land will lead to 30% land uncultivated within 25 years and this number will reach up to 50% by the year 2050 as reported by Valliyodan (2006). Molecular control mechanisms for abiotic stress tolerance are based on activation and regulation of specific stress-related genes. It has been reported by Zhu 2001, that salt tolerant plants also often tolerate other stresses including chilling, freezing heat and drought. Already, a number of abiotic stress tolerant, high performance GM crop plants have been developed. These include tobacco [22]; Arabinopsis thaliana and Brasicca napus [23]; Tomato (Hsieh et al., 2002); rice (Yamanouchi et al., 2002); maize, cotton, wheat and oilseed rape (Yamaguchi and Blumwals, 2005; Brookes and Barfoot, 2006).

These transgenic plants maintained higher photosynthetic capacity and elevated levels of photosynthesis-related enzymes. Recently, a gene encoding aquaporin (NtAQP1) was identified in tobacco (Nicotiana tabacum) and shown to provide protection against salinity stress in transgenic tomato (Solanum lycopersicum) [24]. NtAQP1 plays a key role in preventing root or shoot hydraulic failure, enhancing water use efficiency and thereby improving salt tolerance. Recently, a large body of study shows that plant Polyamines (PAs) are involved in the achievement of tolerance to such stresses as high and low temperatures, salinity, hyper osmosis, hypoxia and atmospheric pollutants [25,26]. I hereby summarized in Table 3 few transgenic plants engineered to make Polyamines for boosted abiotic stress tolerance. Plants may also be engineered to reduce the levels of poly (ADP ribose) polymerise, a key stress related enzyme, resulting in plants that are able to survive drought compared to their non-GM counterparts. Field trial results have shown a 44% increase in yield in favour of such GM crop plants [17]. With the availability of whole genome sequences of plants, physical maps, genetics and functional genomics tools, integrated approaches using molecular breeding and genetic engineering offer new opportunities for improving stress resistance [21].

Table 3: Transgenic plants engineered to synthesize Polyamines for enhanced abiotic stress tolerance.

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Source: Sarvajeet and Narendra [51].

Recent technology developments allow studies of such stress responses at a global molecular scale using omics data (metabolome, proteome and transcriptome). The following studies are discussed to highlight good examples of System biology and omics approaches that have been used to identify key genes regulating stress tolerance and then followed with proof of those responses and phenotypes in multiple experiments including field conditions. One of the example is a SNAC1 (NAC transcription factor that induces the expression of a stress-tolerance genes and improves the drought and salt tolerance of rice in the field) gene which was identified from microarray experiments of stress treatments on rice [24]. The transgenic plants exhibited increased sensitivity to ABA and reduced water loss. An exhaustive screen of greater than 1500 transcription factors in Arabidopsis identified nearly 40 transcription factors that when over expressed, improved stress tolerance [27]. One of these transcription factors NF-YB1 was further characterized and shown to display significant drought tolerance in Arabidopsis. Microarray data of this over expressing line showed few differences in gene expression and the genes identified were not known previously to be involved in drought tolerance.

This functional genomics approach provided a new strategy for improving drought tolerance in plants. A homolog of NF-YB1 was cloned in maize (ZmNF-YB2), over expressed and tested for drought tolerance in the greenhouse and field plots. The transgenic maize lines were more droughts tolerant having increased chlorophyll content, photosynthesis, stomatal conductance and grain yields. One line consistently had more than 50% yield improvement in drought conditions over two different years. Oh et al. [28] used microarrays to identify 42 AP2 transcription factors whose expressions were affected by stress. The two transcription factors are meticulously linked but have distinct differences in affecting rice phenotype. AP37 responded to drought, salinity, cold and ABA; over-expression improved stress tolerance to all three environmental conditions. AP59 responded improved stress tolerance to drought and salinity only. Both over expressing lines showed improved photosynthetic efficiency under stress conditions.

Mycobiotechnology

Climate change is major challenge that is already affecting people and the environment by changing average global temperature mitigates the negative effects of extreme temperature and precipitation thereby reducing the vulnerability of farmers and ecology by improving the agro ecological resistance [29-38]. Mycobiotechnology is fungal application of biotechnology which is used mainly for solving environmental problems and restore degraded ecosystem. These technique endeavor to use fungi for restoration harmed ecology. Saikia [20] reported that both endo and ectomycorrhizal symbiotic fungi together with actinomycetes have been used as inoculants for regeneration of degraded forests. Myco biotechnology, are part of a larger trend toward using living systems to solve environmental problems and restore degraded ecosystems. Now a day the sciences of myco forestry and myco restoration are part of an emerging field of research and application for regeneration of degraded forest ecosystems [39]. Myco restoration attempts to use fungi to help in restoration of ecologically injured environments. Whether the environments have been damaged from anthropogenic or natural disasters, saprophytic and mycorrhizal fungi can help to navigate the course to recovery.

A number of non-legume woody plants such as casuarinas (Casuartna sp.) and alders (Alnus sp.) can fix nitrogen symbiotically with actinomycete bacteria (Frankia sp.), a phenomenon that is beneficial to forestry and agro forestry [40-42]. Both endo and ectomycorrhizal symbiotic fungi together with actinomycetes have been used as inoculants in regeneration of degraded forests [20]. Consequently, both mycorrhizal fungi and actinorhizal bacteria technologies can be applied with the aim of increasing soil fertility and improving water uptake by plants [18]. A forestation would indirectly contribute to improved agricultural productivity and food security because forests create microclimates that improve rainfall availability. Moreover, forests act as carbon sinks thereby contributing in sequestration and greenhouse reduction effects for climate change mitigation. Consequently, forestry and agro forestry offer the potential to develop synergies between efforts to mitigate climate change and efforts to help vulnerable populations to adapt to negative consequences of climate change [43].

Challenges and Futures Line of Work

Climate change has far reaching implications for food security, health and safety, and approaches are required for adapting to new climates. Impacts of climate change are becoming evident and there is no indication that these will reverse in the foreseeable future; action must be taken now to adapt in a timely manner and prevent unpredictable and undesirable outcomes. The world population, currently at 7 billion, is predicted to increase to 8 billion by 2025 and peak at about 9 billion in 2050 [44-47]. According to Ruane [18] developing countries will need to cultivate 120 million additional hectares by crops for feeding ever increasing populations. Therefore, modern agricultural science should implement to boost crop production. Efforts should be made to incorporate local and conventional biotechnologies with modern biotechnology approaches within national policies and legal frameworks in order to increase resilience of local crop varieties against changes in environmental dynamics Stinger et al. 2009.

Though promising result was obtained from modern biotechnology, abundant applications of biotechnology have not encountered their full potential. Of many challenges the major challenges was presented below.

a) Doubt about the cause of climate variation (Natural or Human made) [48-52].

b) Biotic and abiotic stress threatens for food production to feed ever increasing population [21].

c) Raises questions about public safety issues with related to environment and health including: creation of more rigorous pests and pathogens, exacerbating the effects of existing pests, harm to non-target species, disruption of biotic communities and loss of species and genetic diversity within species [34].

d) Raises ethical and socio - cultural issues like loss of traditional crops and fear of the unknown future [35].

e) The role of Polyamines for the abiotic stress tolerance is just commencement to be understood. A lot of effort is still required to uncover in detail the molecular mechanism of protective role of Spd, Spm and Put in abiotic stress tolerance.

In order to solve the challenges presently faced in development and application of modern biotechnology, governments ought to put in place appropriate bio safety and biotechnology policies and legal frameworks before adopting such technologies [53-57]. Anxieties on negative effects of GMOs have to Science based and should be studied case by case in specifying in details with true evidence. Both conventional and modern biotechnology involvements are needed to elucidate the problem. Polarized thought should be based on science not from self or political interest.

Conclusion

To sum up access to information and expertise in developing countries, where the need to counteract climate change and increase food production is most urgent and will be a key factor in the use of biotechnology for continued production. Plant biotechnology can contribute positively towards climate change adaptation and mitigation through reduction of green houses gas emissions, carbon sequestration, less fuel use and energy efficient farming and reduced artificial use. This measures help to improve agricultural productivity and protecting the ecosystem from extreme weather event. Sound application of modern biotechnology will help to counteract climate related problems and thereby securing crop production for fast growing population. An approach to safe applications of modern agricultural biotechnologies will contribute to increased yield, food security and also it will also significantly contribute to climate change adaptation and mitigation initiatives.

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