Genome Editing

Increased agricultural production and sustainable food security is of utmost importance for the rapidly increasing global population. Successful development of crop varieties with improved agronomic traits such as high yield, and biotic and abiotic stress tolerance can have a great impact on agricultural productivity. However, the current trends in the production of agricultural food crops may not be enough to provide sustainable solutions unless innovative technologies are adopted to meet the growing needs. New breeding technologies such as genome editing by CRISPR/ Cas (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein) can be harnessed to achieve sustainability in agriculture by modifying target genes precisely. These tools can be used to create crop varieties with desired features for increasing agricultural productivity.

Developments in targeted genome editing ensure that the CRISPR components that are used to edit the selected native genes for a desirable trait and the antibiotic resistant gene used for selecting the edited line can easily be removed by segregation of the plant progeny in the next and subsequent generations. In this way, one can produce transgene-free edited plants that are indistinguishable from plants that can be obtained through conventional breeding.

Rice is one of the most important staple food crops on which over 3.5 billion people are dependent for daily energy consumption. With increasing water scarcity in agriculture, cultivating rice in the conventional puddled ecosystem is becoming uneconomical. Growing rice under non-puddled conditions such as direct seeding, alternate wetting and drying, and aerobic cultivation saves substantial amounts of water. However, infestation with biotic factors like weeds, pests and pathogens diminish water saving advantages of aerobic cultivation and reduce productivity under irrigated conditions. Genome editing of appropriate alleles would accelerate the process of generating rice cultivars for target environments.

Team
VS Sresty Tavva, Rambabu Ratnala

Activities:

Rice is one of the most important staple food crops on which most people are dependent on for daily energy consumption. Rice is a water intesnive crop which accounts for more than half of all the fresh water used in agriculture. With increasing water scarcity in agriculture, cultivating rice in the conventional puddled ecosystem is increasingly becoming uneconomical. Therefore, growing rice under non-puddled conditions such as direct seeding and aerobic cultivation save substantial amounts of water. However, infestation with biotic factors like weeds and pathogens diminish the water saving advantage of aerobic cultivation and also reduce productivity under irrigated conditions. Genome editing of appropriate alleles would accelerate the process of generating rice cultivars for target environments.

We are working towards developing bacterial leaf blight resistance through genome editing of appropriate alleles in the background of aerobic rice cultivar (KMP175) and a mega variety (MTU1010). Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae is one of the most devastating diseases restricting rice production. It spreads systematically through the leaf xylem tissue and infection leads to significant yield losses. More than 38 BLB genes have been identified so far in rice and the recessive sweet11, sweet13 and sweet14 genes provide broad-spectrum resistance genes to BLB (Chu et al., 2006; Oliva et al., 2019). Suppressing the expression of SWEET genes can result in the development of resistance to BLB isolates, PthXo1, PthXo2, PthXo3 and AvrXa7 (Oliva et al., 2019).

Investigator: VS Sresty Tavva

Collaborator:
University of Agricultural Sciences (UAS), GKVK, Bengaluru

Many popular Indica rice cultivars are highly susceptible to insect pests, leading to huge yield losses. One way around it is development of insect pest resistance in high yielding rice cultivars. We undertake CRISPR/Cas9 mediated genome editing to generate target mutations for increased resistance to insect pests brown planthopper (BPH) and striped stem borer (SSB) in popular indica rice cultivars.

The final product generated will be a rice variety that will be helpful to farmers who face huge yield losses due to these pests. It will also contribute to a reduction in the massive use of pesticides and chemicals to control insect pests in order to provide environmentally friendly and chemical-free rice to society. Insect resistant Indica lines created in this project will serve as an excellent source of germplasm and will be transmitted to a popular background.

Investigator: Rambabu Ratnala

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