scholarly journals Alternative Strategies for Multi-Stress Tolerance and Yield Improvement in Millets

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 739
Author(s):  
Muhammad Numan ◽  
Desalegn D. Serba ◽  
Ayalew Ligaba-Osena

Millets are important cereal crops cultivated in arid and semiarid regions of the world, particularly Africa and southeast Asia. Climate change has triggered multiple abiotic stresses in plants that are the main causes of crop loss worldwide, reducing average yield for most crops by more than 50%. Although millets are tolerant to most abiotic stresses including drought and high temperatures, further improvement is needed to make them more resilient to unprecedented effects of climate change and associated environmental stresses. Incorporation of stress tolerance traits in millets will improve their productivity in marginal environments and will help in overcoming future food shortage due to climate change. Recentlly, approaches such as application of plant growth-promoting rhizobacteria (PGPRs) have been used to improve growth and development, as well as stress tolerance of crops. Moreover, with the advance of next-generation sequencing technology, genome editing, using the clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) system are increasingly used to develop stress tolerant varieties in different crops. In this paper, the innate ability of millets to tolerate abiotic stresses and alternative approaches to boost stress resistance were thoroughly reviewed. Moreover, several stress-resistant genes were identified in related monocots such as rice (Oryza sativa), wheat (Triticum aestivum), and maize (Zea mays), and other related species for which orthologs in millets could be manipulated by CRISPR/Cas9 and related genome-editing techniques to improve stress resilience and productivity. These cutting-edge alternative strategies are expected to bring this group of orphan crops at the forefront of scientific research for their potential contribution to global food security.

2020 ◽  
Vol 44 (2) ◽  
pp. 121-127
Author(s):  
Tae Hyun

Climate change is affecting agriculture in a number of ways, such as changing water distribution, daily temperatures and salinity patterns. In this regard, plant breeding innovations and genetic engineering approaches to improve abiotic stress tolerance are necessary to avoid a decline in crop yields caused by climate change during the 21st century. In the last few years, genome editing using the CRISPR/Cas system has attracted attention as a powerful tool that can generate hereditary mutations. So far, only a few studies using the CRISPR/Cas system have been reported to improve abiotic stress tolerance, but they have clearly suggested its effective role for future applications in molecular breeding to improve abiotic stress tolerance. Accordingly, the CRISPR/Cas system application is introduced in this mini-review as a way to improve abiotic stress tolerance. Although editing efficiency and target discovery for plant CRISPR/Cas systems require further improvement, CRISPR/Cas systems will be the key approach to maintaining global food security during climate change.


Author(s):  
Ali Razzaq ◽  
Ghulam Mustafa ◽  
Muhammad Amjad Ali ◽  
Muhammad Sarwar Khan ◽  
Faiz Ahmad Joyia

Abstract This chapter discusses the applications of CRISPR-mediated genome editing to improve the abiotic stress tolerance (such as drought, heat, waterlogging and cold tolerance) of maize. CRISPR/Cas9 has great potential for maize genome manipulation at desired sites. By using CRISPR/Cas9-mediated genome editing, numerous genes can be targeted to produce elite maize cultivars that minimize the challenges of abiotic stresses. In the future, more precise and accurate variants of the CRISPR/Cas9 toolbox are expected to be used for maize yield improvement.


Author(s):  
Diksha Sati ◽  
Veni Pande ◽  
Satish Chandra Pandey ◽  
Mukesh Samant

Increased severity of droughts, due to anthropogenic activities and global warming has imposed a severe threat on agricultural productivity ever before. This has further advanced the need for some eco-friendly approaches to ensure global food security. In this regard, application of plant growth-promoting rhizobacteria (PGPR) can be beneficial. PGPR through various mechanisms viz. osmotic adjustments, increased antioxidant, phytohormone production, regulating stomatal conductivity, increased nutrient uptake, releasing Volatile organic compounds (VOCs), and Exo-polysaccharide (EPS) production, etc not only ensures the plant’s survival during drought but also augment its growth. This review, extensively discusses the various mechanisms of PGPR in drought stress tolerance. We have also summarized the recent molecular and omics-based approaches for elucidating the role of drought responsive genes. The manuscript presents an in-depth mechanistic approach to combat the drought stress and also deals with designing PGPR based bioinoculants. Lastly, we present a possible sequence of steps for increasing the success rate of bioinoculants.


2021 ◽  
Vol 22 (2) ◽  
pp. 682
Author(s):  
Hymavathi Salava ◽  
Sravankumar Thula ◽  
Vijee Mohan ◽  
Rahul Kumar ◽  
Fatemeh Maghuly

Plants regularly face the changing climatic conditions that cause biotic and abiotic stress responses. The abiotic stresses are the primary constraints affecting crop yield and nutritional quality in many crop plants. The advances in genome sequencing and high-throughput approaches have enabled the researchers to use genome editing tools for the functional characterization of many genes useful for crop improvement. The present review focuses on the genome editing tools for improving many traits such as disease resistance, abiotic stress tolerance, yield, quality, and nutritional aspects of tomato. Many candidate genes conferring tolerance to abiotic stresses such as heat, cold, drought, and salinity stress have been successfully manipulated by gene modification and editing techniques such as RNA interference, insertional mutagenesis, and clustered regularly interspaced short palindromic repeat (CRISPR/Cas9). In this regard, the genome editing tools such as CRISPR/Cas9, which is a fast and efficient technology that can be exploited to explore the genetic resources for the improvement of tomato and other crop plants in terms of stress tolerance and nutritional quality. The review presents examples of gene editing responsible for conferring both biotic and abiotic stresses in tomato simultaneously. The literature on using this powerful technology to improve fruit quality, yield, and nutritional aspects in tomato is highlighted. Finally, the prospects and challenges of genome editing, public and political acceptance in tomato are discussed.


Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 337
Author(s):  
Rafael J. L. Morcillo ◽  
Maximino Manzanera

Plant growth-promoting rhizobacteria (PGPR) are beneficial soil microorganisms that can stimulate plant growth and increase tolerance to biotic and abiotic stresses. Some PGPR are capable of secreting exopolysaccharides (EPS) to protect themselves and, consequently, their plant hosts against environmental fluctuations and other abiotic stresses such as drought, salinity, or heavy metal pollution. This review focuses on the enhancement of plant abiotic stress tolerance by bacterial EPS. We provide a comprehensive summary of the mechanisms through EPS to alleviate plant abiotic stress tolerance, including salinity, drought, temperature, and heavy metal toxicity. Finally, we discuss how these abiotic stresses may affect bacterial EPS production and its role during plant-microbe interactions.


Author(s):  
Showkat Ahmad Ganie ◽  
Javaid Akhter Bhat ◽  
Alessandra Devoto

Abstract Key Message Endophytes are crucial for the promotion of rice growth and stress tolerance and can be used to increase rice crop yield. Endophytes can thus be exploited in biotechnology and genetic engineering as eco-friendly and cost-effective means for the development of high-yielding and stress-tolerant rice plants. Abstract Rice (Oryza sativa) crop is continuously subjected to biotic and abiotic stresses, compromising growth and consequently yield. The situation is exacerbated by climate change impacting on ecosystems and biodiversity. Genetic engineering has been used to develop stress-tolerant rice, alongside physical and chemical methods to mitigate the effect of these stresses. However, the success of these strategies has been hindered by short-lived field success and public concern on adverse effects associated. The limited success in the field of stress-tolerant cultivars developed through breeding or transgenic approaches is due to the complex nature of stress tolerance as well as to the resistance breakdown caused by accelerated evolution of pathogens. It is therefore necessary to develop novel and acceptable strategies to enhance rice stress tolerance and durable resistance and consequently improve yield. In the last decade, plant growth promoting (PGP) microbes, especially endophytes, have drawn the attention of agricultural scientists worldwide, due to their ability to mitigate environmental stresses in crops, without causing adverse effects. Increasing evidence indicates that endophytes effectively confer fitness benefits also to rice under biotic and abiotic stress conditions. Endophyte-produced metabolites can control the expression of stress-responsive genes and improve the physiological performance and growth of rice plants. This review highlights the current evidence available for PGP microbe-promoted tolerance of rice to abiotic stresses such as salinity and drought and to biotic ones, with special emphasis on endophytes. Associated molecular mechanisms are illustrated, and prospects for sustainable rice production also in the light of the impending climate change, discussed.


2021 ◽  
Vol 28 ◽  
Author(s):  
Temoor Ahmed ◽  
Muhammad Shahid ◽  
Muhammad Noman ◽  
Sher Muhammad ◽  
Muhammad Tahir ul Qamar ◽  
...  

Abstract: Abiotic stresses in plants such as salinity, drought, heavy metal toxicity, heat, and nutrients limitations significantly reduce agricultural production worldwide. The genome editing techniques such as transcriptional activator-like effector nucleases (TALENs) and zinc finger nucleases (ZFNs) have been used for genome manipulations in plants. However, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technique has recently emerged as a promising tool for genome editing in plants to acquire desirable traits. The CRISPR/Cas9 system has a great potential to develop crop varieties with improved tolerance against abiotic stresses. This review is centered on the biology and potential application of the CRISPR/Cas9 system to improve abiotic stress tolerance in plants. Furthermore, this review highlighted the recent advancements of CRISPR/Cas9-mediated genome editing for sustainable agriculture.


Author(s):  
Mark Cooper ◽  
Kai P. Voss-Fels ◽  
Carlos D. Messina ◽  
Tom Tang ◽  
Graeme L. Hammer

Abstract Key message Climate change and Genotype-by-Environment-by-Management interactions together challenge our strategies for crop improvement. Research to advance prediction methods for breeding and agronomy is opening new opportunities to tackle these challenges and overcome on-farm crop productivity yield-gaps through design of responsive crop improvement strategies. Abstract Genotype-by-Environment-by-Management (G × E × M) interactions underpin many aspects of crop productivity. An important question for crop improvement is “How can breeders and agronomists effectively explore the diverse opportunities within the high dimensionality of the complex G × E × M factorial to achieve sustainable improvements in crop productivity?” Whenever G × E × M interactions make important contributions to attainment of crop productivity, we should consider how to design crop improvement strategies that can explore the potential space of G × E × M possibilities, reveal the interesting Genotype–Management (G–M) technology opportunities for the Target Population of Environments (TPE), and enable the practical exploitation of the associated improved levels of crop productivity under on-farm conditions. Climate change adds additional layers of complexity and uncertainty to this challenge, by introducing directional changes in the environmental dimension of the G × E × M factorial. These directional changes have the potential to create further conditional changes in the contributions of the genetic and management dimensions to future crop productivity. Therefore, in the presence of G × E × M interactions and climate change, the challenge for both breeders and agronomists is to co-design new G–M technologies for a non-stationary TPE. Understanding these conditional changes in crop productivity through the relevant sciences for each dimension, Genotype, Environment, and Management, creates opportunities to predict novel G–M technology combinations suitable to achieve sustainable crop productivity and global food security targets for the likely climate change scenarios. Here we consider critical foundations required for any prediction framework that aims to move us from the current unprepared state of describing G × E × M outcomes to a future responsive state equipped to predict the crop productivity consequences of G–M technology combinations for the range of environmental conditions expected for a complex, non-stationary TPE under the influences of climate change.


2021 ◽  
Vol 22 (15) ◽  
pp. 7877
Author(s):  
Fahimeh Shahinnia ◽  
Néstor Carrillo ◽  
Mohammad-Reza Hajirezaei

Environmental adversities, particularly drought and nutrient limitation, are among the major causes of crop losses worldwide. Due to the rapid increase of the world’s population, there is an urgent need to combine knowledge of plant science with innovative applications in agriculture to protect plant growth and thus enhance crop yield. In recent decades, engineering strategies have been successfully developed with the aim to improve growth and stress tolerance in plants. Most strategies applied so far have relied on transgenic approaches and/or chemical treatments. However, to cope with rapid climate change and the need to secure sustainable agriculture and biomass production, innovative approaches need to be developed to effectively meet these challenges and demands. In this review, we summarize recent and advanced strategies that involve the use of plant-related cyanobacterial proteins, macro- and micronutrient management, nutrient-coated nanoparticles, and phytopathogenic organisms, all of which offer promise as protective resources to shield plants from climate challenges and to boost stress tolerance in crops.


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