AHLs' life in plants: Especially their potential roles in responding to Fusarium wilt and repressing the seed oil accumulation.

Members of the AT-hook motif nuclear localized (AHL) family contain diverse but poorly understood biological functions. We identified 371 AHLs in 20 land plants, varying from the early diverging lycophyte Selagineila moellendorfi to a variety of higher plants. The AHLs were divided into two clades (Clade-A and Clade-B) with three different types (Type-I, Type-II, and Type-III AHLs). The divergence between Clade-A and Clade-B likely occurred before the separation of S. moellendorfi from the vascular plant lineages. Members of the AHLs family expanded with the specific whole-genome duplication (WGD)/segmental duplication in some genomes, such as Hevea brasiliensis. The ortholog (Vf00G1914/Amo018442) exhibited opposite expression patterns between two Vernicia species (V. fordii and V. montana), indicating that it was implicated in resistance to Fusarium wilt disease. The expression of Vf09G2138 exhibited a negative correlation with lipid biosynthesis in V. fordii seeds during different stages of development, suggesting that this gene might repress the seed oil accumulation. The core AT-hook motif and PPC domain were responsible for guiding the localization of AHL in the nucleus. This study helps us to understand the evolution of AHLs in multiple plants, further highlight their functions during V. fordii seed development and response to Fusarium wilt disease.