Answer:
Rice plants possesses several traits which allow sthem to grow in large amount of water because standing water helps them to produce air channel known as aerenchyma that connects roots with shoots and transport oxygen to submerged tissues. Standing water also help many weed to grow and rice plants also takes nutrients from them as well.
Genes are responsible for the traits that allow rice plants to grow in large amount of water but if the gene of rice plant is genetically modified with new gene which is resistant to drought, that can allow the rice to grow in less water.
The genetically modified rice plant then do not require large amount of water and can grow easily.