Japonica Rice

Source: TH

Context: Scientists at the National Institute of Plant Genome Research (NIPGR) have used CRISPR-Cas9 gene-editing to enhance phosphate uptake in japonica rice, leading to a 20–40% increase in yield under controlled phosphate use.

About Japonica Rice:

• What is Japonica Rice? Japonica rice is a short-grain, high-starch variety of rice primarily grown in East Asia, often used in breeding experiments due to its ease of genetic modification and stable traits in controlled environments.

• Japonica rice is a short-grain, high-starch variety of rice primarily grown in East Asia, often used in breeding experiments due to its ease of genetic modification and stable traits in controlled environments.

• Developed By:

• Developed by NIPGR, New Delhi, using CRISPR-Cas9 gene editing Research published in the Plant Biotechnology Journal Cultivar used: Nipponbare (a model japonica variety)

• Developed by NIPGR, New Delhi, using CRISPR-Cas9 gene editing

• Research published in the Plant Biotechnology Journal

• Cultivar used: Nipponbare (a model japonica variety)

• How Was It Developed?

• Target Gene Identified: OsPHO1;2, a phosphate transporter moving phosphorus from root to shoot Repressor Found: OsWRKY6, a negative regulator of this transporter Initial Strategy Failed: Knocking out the repressor impaired other plant functions Precise Editing: Only the 30 base-pair binding sites of the repressor was removed using CRISPR Outcome: Increased phosphate flow to the shoot, leading to better seed development

• Target Gene Identified: OsPHO1;2, a phosphate transporter moving phosphorus from root to shoot

• Repressor Found: OsWRKY6, a negative regulator of this transporter

• Initial Strategy Failed: Knocking out the repressor impaired other plant functions

• Precise Editing: Only the 30 base-pair binding sites of the repressor was removed using CRISPR

• Outcome: Increased phosphate flow to the shoot, leading to better seed development

• Key Features of Gene-Edited Japonica Rice:

• 20% higher yield with full fertilizer dose and 40% yield gain with only 10% of recommended phosphate. Increased phosphate absorption due to improved transporter activation. More panicles and seeds, while seed quality and dimensions remained normal. No foreign DNA in final generation; removed via Mendelian segregation. No off-target effects detected; validated using top genome-prediction software. Successfully simulates minimal-invasive promoter gene surgery.

• 20% higher yield with full fertilizer dose and 40% yield gain with only 10% of recommended phosphate.

• Increased phosphate absorption due to improved transporter activation.

• More panicles and seeds, while seed quality and dimensions remained normal.

• No foreign DNA in final generation; removed via Mendelian segregation.

• No off-target effects detected; validated using top genome-prediction software.

• Successfully simulates minimal-invasive promoter gene surgery.

• Significance for India:

• Reduces Dependence on DAP Imports: India imports ~4.5 million tonnes annually. Tackles Phosphorus Deficiency: Crucial for Indian soils suffering nutrient loss. Eco-Friendly Agriculture: Optimizes phosphate use, reducing runoff and pollution. Future Prospects: Potential replication in indica rice, India’s major cultivar. Boost to Food Security: Improves productivity in nutrient-limited conditions.

• Reduces Dependence on DAP Imports: India imports ~4.5 million tonnes annually.

• Tackles Phosphorus Deficiency: Crucial for Indian soils suffering nutrient loss.

• Eco-Friendly Agriculture: Optimizes phosphate use, reducing runoff and pollution.

• Future Prospects: Potential replication in indica rice, India’s major cultivar.

• Boost to Food Security: Improves productivity in nutrient-limited conditions.