Unlike most animals, plants have multiple copies of RNase T2 genes in their genomes. Our analyses showed that this family has undergone a significant adaptive radiation, with evidences of positive selection and gene sorting, indicative of neofunctionalization. To gain a better understanding of these phenomena, we characterized several plant RNase T2 proteins that are not involved in vacuolar degradation of rRNA, from rice, petunia, tobacco, and Arabidopsis. We found that these proteins have gained a diversity of functions, from defensive antimicrobial roles to components of a phosphate scavenging system that is triggered when plants grow under P starvation.

Localization of NnSR1-Cer in endoplasmic reticulum of Arabidopsis leaf protoplasts
Figure from Rojas et al (2015) Plant Science, 236, 250-259