AINTEGUMENTA-like (AIL) genes are expressed in young tissues and may specify meristematic or division-competent states

Abstract

Although several members of the AP2/ERF family of transcription factors are important developmental regulators in plants, many genes in this large protein family remain uncharacterized. Here, we present a phylogenetic analysis of the 18 genes that make up the AP2 subgroup of this family. We report expression analyses of seven Arabidopsis genes most closely related to the floral development gene AINTEGUMENTA (ANT) and show that all AINTEGUMENTA-like (AIL) genes are transcribed in multiple tissues during development. They are expressed primarily in young actively dividing tissues of a plant and not in mature leaves or stems. The spatial distribution of AIL5, AIL6, and AIL7 mRNA in inflorescences was characterized by in situ hybridization. Each of these genes is expressed in a spatially and temporally distinct pattern within inflorescence meristems and flowers. Ectopic expression of AIL5 resulted in a larger floral organ phenotype, similar to that resulting from ectopic expression of ANT. Our results are consistent with AIL genes having roles in specification of meristematic or division-competent states.

AINTEGUMENTA negatively regulates age-dependent leaf senescence downstream of AUXIN RESPONSE FACTOR 2 in <i>Arabidopsis thaliana</i>

“…In Arabidopsis, AP2/ERF proteins make up one of the largest transcription factor families. ANT and AINTEGUMENTA-like (AIL) belong to the AP2 subfamily that consists of 18 members (Riechmann et al 2000) and have redundant roles in specification of meristematic or division-competent states (Nole-Wilson et al 2005). For example, ectopic expression of AIL5 in wild type plants produces larger floral organs just like that in the transgenic plant overexpressing ANT (NoleWilson et al 2005).…”

“…ANT promotes organ growth by maintaining meristem competence and increasing cell numbers. ANT is expressed primarily in young actively dividing tissues of a plant, and low expression is observed by real time RT-PCR in mature leaves but not by RNA gel blot analysis, suggests that the expression of ANT is age-dependent (Klucher et al 1996;Nole-Wilson et al 2005). It is very interesting to study the relationship of ANT and ARF2 in the age-dependent leaf senescence.…”

SEUSSandAINTEGUMENTAMediate Patterning and Ovule Initiation during Gynoecium Medial Domain Development

“…ANT is a member of a family of transcriptional regulators, the AIL gene family (Nole-Wilson et al, 2005). The expression of several members of the AIL family within the gynoecium overlaps with that of ANT suggesting that these genes may provide some functional redundancy.…”

“…These three functions support medial domain development and ovule initiation in wild-type gynoecia. Additional members of the SLK (Franks et al, 2002;Navarro et al, 2004), AIL (Nole-Wilson et al, 2005), YABBY (Siegfried et al, 1999), and LUG/LEUNIG-HOMOLOGUE (Conner and Liu, 2000) gene families are likely to provide molecular redundancy by also participating in this multicomponent molecular complex. Mutant combinations that disrupt at least two of these protein subunits can result in a dramatic loss of the gynoecium medial domain (e.g.…”

The AINTEGUMENTA LIKE1 Homeotic Transcription Factor PtAIL1 Controls the Formation of Adventitious Root Primordia in Poplar

“…This superfamily consists of 145 members in Arabidopsis (Sakuma et al, 2002;Zhuang et al, 2008), 157 in rice (Oryza sativa; Nakano et al, 2006), and 210 in poplar (according to the database of transcriptional factors in poplar (http://planttfdb.cbi.pku.edu.cn/). AtAP2 subfamily members such as PLETHORA1 (AtPLT1) and AtPLT2, BABY BOOM (AtBBM), AIN-TEGUMENTA (AtANT), and AINTEGUMENTA-like (AtAIL) genes regulate a number of developmental processes Mizukami and Fischer, 2000;Mizukami, 2001;Nole-Wilson et al, 2005;Imin et al, 2007). ANT is part of a pathway that regulates floral organ initiation and growth , and it also contributes to the specification of organ polarity by interacting with other genes (Nole-Wilson and .…”