Altered expression of OsNPF7.1 and OsNPF7.4 differentially regulates tillering and grain yield in rice.

The rice nitrate and di/tripeptide transporter (NPF) gene family plays an indispensable role in nitrogen transport and plant growth. In this study, 18 alternatively spliced OsNPF genes with 36 different forms of mRNAs were identified, and two of these, namely OsNPF7.1 and OsNPF7.

Rice nitrate transporter OsNPF7.2 positively regulates tiller number and grain yield.

Background: Rice tiller number is one of the most important factors that determine grain yield, while nitrogen is essential for the crop growth and development, especially for tiller formation. Genes involved in nitrogen use efficiency processes have been identified in the previous studies, however, only a small number of these genes have been found to improve grain yield by promoting tillering.

Results: We constructed over-expression (OX) lines and RNA-interference (Ri) lines, and selected a mutant of OsNPF7.

Blocking amino acid transporter OsAAP3 improves grain yield by promoting outgrowth buds and increasing tiller number in rice.

Amino acid transporters (AATs) play indispensable roles in nutrient allocation during plant development. In this study, we demonstrated that inhibiting expression of the rice amino acid transporter OsAAP3 increased grain yield due to a formation of larger numbers of tillers as a result of increased bud outgrowth. Elevated expression of OsAAP3 in transgenic plants resulted in significantly higher amino acid concentrations of Lys, Arg, His, Asp, Ala, Gln, Gly, Thr and Tyr, and inhibited bud outgrowth and rice tillering.