Tiller number is important in rice yield, as it projects the number of panicle that will be produced by the plant. Through overexpression and knock-out experiments, researcher Zhongming Fang from Huazhong Agricultural University and colleagues found that gene OsAAP3 significantly controls tillering number and outgrowth bud formation in rice.

OsAAP3 is a gene coding for an amino acid transporter, which is important in delivering nutrients such as inorganic nitrogen to different parts of the plant. OsAAP3 transports Ser, Met, Lys, Leu, His, Gln, Arg, Ala, and Gly from source to sink organs of the plant. Overexpressing the gene showed decreased tillering in Japonica rice. By contrast, knocking out OsAAP3 using CRISPR-Cas9 boosted the yield and outgrowth bud formation in rice. Overall, the inhibition of OsAAP3 expression may be used in boosting yield and nitrogen use efficiency in rice.

For more information, read the article in Plant Biotechnology Journal.