“Genome Edited” Rice in India and the Potential for Genome Editing for Rice Weed Management

Adusumilli Narayana Rao and Nimal Chandrasena

Keywords:

CRISPR-Cas9, Genome editing, India, Herbicide-tolerant rice, Weed management

Abstract:

Innovative crop and weed management technologies are necessary to meet the food and nutrition demands of an increasingly global population while addressing other challenges. The challenges that people face worldwide include a changing climate, limited cultivable land, erratic weather patterns and the emergence of new pests, diseases and weeds with greater adaptability to a changing climate. This paper aims to synthesise information on the recent practical applications and successes of gene editing technology in developing two multiple stress-tolerant, high-yielding rice varieties in India. We commend this new development and discuss the possibility of utilising gene editing technology to improve various components of integrated weed management in rice. Recently, two rice varieties, viz. DRR Dhan 100 (Kamala) and Pusa DSR Rice were developed by the Indian Council of Agricultural Research (ICAR), India, using the CRISPR-Cas9 genome-editing technology. India is the first country in the world to develop and approve genome-edited rice varieties using gene editing technology that does not involve genetically modified organisms. These varieties, developed under the project “Enhancing climate resilience and ensuring food security with genome editing tools,” are early maturing by 20 days and have significantly improved drought and salinity tolerance, as well as nitrogen-use efficiency in rice. Simultaneously, the varieties provide higher yields while reducing methane emissions. Other areas where gene editing technology may be utilised to enhance components of Integrated Weed Management (IWM) in rice include the development of herbicide-tolerant (HT) rice varieties through targeted genome editing and modifying the genes involved. Recent advances in gene editing, particularly ‘gene drives’, also offer promising tools and novel approaches that can modify weed populations, making them more susceptible to weed management tactics. Gene technology may also help produce rice varieties that are less susceptible to competition from weeds. This would require identifying novel quantitative trait loci (QTLs) and genes/alleles related to competitive abilities in major rice weeds, as well as allelopathy traits in rice. Gene editing may then lead to the production of weed-competitive and strongly allelopathic rice varieties that can be bred more successfully. Recent research has also shown that gene editing could be used to make weedy species more visible to machine-learned robots. This paper presents several examples of the potential applications of gene editing, highlighting the capabilities of these new genetic technologies in enhancing the components of integrated weed management. It is possible to predict that IWM in rice is changing rapidly with the novel technologies offering hope for improved management of rice weeds, leading to associated yield improvements.