Submergence Tolerance in Rice: Review of Mechanism, Breeding and, Future Prospects

Abstract

Flooding or submergence is one of the major environmental stressors affecting many man-made and natural ecosystems worldwide. The increase in the frequency and duration of heavy rainfall due to climate change has negatively affected plant growth and development, which eventually causes the death of plants if it persists for days. Most crops, especially rice, being a semi-aquatic plant, are greatly affected by flooding, leading to yield losses each year. Genetic variability in the plant response to flooding includes the quiescence scheme, which allows underwater endurance of a prolonged period, escape strategy through stem elongation, and alterations in plant architecture and metabolism. Investigating the mechanism for flooding survival in wild species and modern rice has yielded significant insight into developmental, physiological, and molecular strategies for submergence and waterlogging survival. Significant progress in the breeding of submergence tolerant rice varieties has been made during the last decade following the successful identification and mapping of a quantitative trait locus for submergence tolerance, designated as SUBMERGENCE 1 (SUB1) from the FR13A landrace. Using marker-assisted backcrossing, the SUB1 QTL (quantitative trait locus) has been incorporated into many elite varieties within a short time and with high precision as compared with conventional breeding methods. Despite the advancement in submergence tolerance, for future studies, there is a need for practical approaches exploring genome-wide association studies (GWA) and QTL in combination with specific tolerance traits, such as drought, salinity, disease and insect resistance.Sustainability 2020, 12, 1632 2 of 16 yield losses annually. For example, as reported by Bailey-Serres et al. [2], in the United States, a 12-year study on losses of crop production revealed that flooding is the second threat after drought. It was reported that these two abiotic stresses (flooding and drought) accounted for a 70% drop in harvest in 2011 alone. In that year, there were insurance payouts of over 3 billion USD due to flooding, with over 1.6 billion paid on soybean and maize. In Pakistan, over 4.45 billion USD worth was lost due to flooding in rice, cotton, and wheat in 2010 [3]. Similarly, an increase in summer rainfall causes water stagnation and flooding, with the event of economic consequences across Europe [4].At the moment, one of the most flood-threatened crops is rice. About 30% (700 million) of people living in abject poverty (i.e., daily income less than 1$) in Asian countries reside in flood-prone rice cultivating regions of South Asia, with Nepal, Bangladesh, and India accounting for half of the above-stated figure. In Nepal, 15% of the total cultivated areas of 1.5 million hectare is affected by floods every year [5]. Similarly, out of 16.1 million hectares of rice-growing areas in India, 5.2 million are occasionally affected by flood, while in Bangladesh, 1.6 million hectares of rice field are periodically affected by flood, out of a tot...

Genetic analysis of microsatellites associated with resistance against bacterial leaf blight and blast diseases of rice (Oryza sativa L.)

“…Figure 4 shows the percentage polymorphism of 472 screened background SSR markers. Suitable marker selection is vital in a markerassisted backcross breeding for selection of target genes while avoiding linkage drag [29][30][31][32]. It also facilitates the recurrent parent genome recovery.…”

Unlocking the inherent potential of plant genetic resources: food security and climate adaptation strategy in Fiji and the Pacific

“…Although extreme submergence or flooding is deleterious to rice cultivation, the crop has tolerance to anaerobic conditions through the development of aerenchyma cells which facilitate transport of oxygen from unsubmerged shoots to submerged roots, and rapid shoot elongation to rise above the flooded soil (Nishiuchi et al 2012 ). However, if floodwaters are very deep or flooding period is long, then once the water recedes, most plants experience lodging and die due to exhaustion of energy reserves (Oladosu et al 2020 ). Rice is however, highly sensitive to soil salinity.…”

Harnessing the Potential of Plant Transcription Factors in Developing Climate-Smart Crops: Future Prospects, Challenges, and Opportunities

“…A dCAPS marker was developed for selection of fruit color in apples at early plant developmental stages using MAB [155]. Another very successful example of MAB is the introduction of the SUB1 region into rice, which increases submergence tolerance without effecting yield, grain quality or development [156]. Similar marker systems could be developed for WRKY and other TFs responding to under various biotic and abiotic stresses for foreground selection prior to plantation of plants in the field.…”

“…Another area of improvement is development of functional marker systems, i.e., SSR markers, SNPs, or dCAPS for MAB of different TFs. Only a few examples exist in literature for development of functional marker systems for characterization of TFs [154][155][156]. Functional markers will help identification of TFs in successive generations for marker-assisted crop improvement.…”