PNH — Nicotiana attenuata

Summary

A4A49_16641 (symbol PNH, also known as AGO7) in coyote tobacco (Nicotiana attenuata) encodes a Piwi/Argonaute-family protein containing PAZ and RNaseH-like domains. The product is annotated with siRNA binding, RNA endonuclease activity, and histone ubiquitin ligase and deubiquitinase activities. AGO7 is associated with miRNA and tasiRNA metabolism, gene silencing by miRNA-directed mRNA cleavage, regulation of epidermis development, somatic stem cell population maintenance, temporal regulation of development, and regulation of secondary metabolism including flavonoid biosynthesis. In this species, AGO7 has been linked to competitive growth. The gene is further connected to leaf polarity and morphology, auxin signalling, juvenile-to-adult transition, and traits including photosynthetic ability, root phototropism, UV light sensitivity, gibberellic acid and cytokinin content, lignin biosynthesis, inflorescence development, and seed dormancy. Studies of related genes in other species link the family to shoot meristem organization, organ polarity, floral development, and heat tolerance.