AarMIXTAs: key factors of T-shaped non-glandular trichome development in Artemisia argyi

Abstract

Trichomes are necessary for stress resistance and metabolite synthesis in plant. T-shaped non-glandular trichomes (TSTs) as the main component of moxa floss, which are the specific characteristics of A. argyi. Here, we observed that TSTs were at an extremely high density on the lower surfaces in A. argyi leaves. The key transcription factors (TFs) involved in regulation of TSTs development of A. argyi were identified through RNA sequencing of TSTs and non-TSTs. The core regulatory genes, AarMIXTAs showed allelic amplification and functional differentiation compared with A. annua, might contribute development of TSTs. The overexpression of AarMIXTA1.2 significantly increased the density of TSTs in transgenic Arabidopsis and may regulate trichome development by regulating the downstream genes, which played an important positively regulatory role in the development of TSTs. This study provides a good reference for the molecular mechanisms related to the development of TSTs and a theoretical basis for the high-yield moxa floss cultivation of A. argyi.