Active suppression of leaflet emergence as a mechanism of simple leaf development

Integration of Core Mechanisms Underlying Plant Aerial Architecture

“…Loss of function for different differentiation factors including NGATHA, TCP, and KNOX-II transcription factors in different combinations, results in differing degrees of continued growth and leaf dissection. Adapted from Furumizu et al (2015) , Alvarez et al (2016) , and Challa et al (2021) .…”

“…In this case, super-compound leaves are formed as leaflets initiate indefinitely ( Figure 6 ). This involves the activation of KNOX-I genes KNAT2 and KNAT6 , which positively regulates CUC2 in a feedback loop ( Challa et al, 2021 ). How an additional loss of NGATHA activity in this background might influence leaf morphology remains an interesting question to follow up.…”

The Genetic Control of the Compound Leaf Patterning in Medicago truncatula

“…The pattern formation is largely dependent on maintaining and modulating a transient morphogenetic activity in the early leaf primordia which directs temporal and spatial patterns of the leaflet initiation ( Bar and Ori, 2015 ). In most compound-leafed species including tomato and C. hirsuta , in addition to the role in promoting and maintaining SAM indeterminacy, KNOX I genes also play a key role in maintaining transient indeterminacy and morphogenetic activity in early compound leaf primordia ( Hareven et al, 1996 ; Hay and Tsiantis, 2006 ; Challa et al, 2021 ). As mentioned above, KNOX I genes are specifically expressed in SAM and are down regulated in the incipience of leaf primordium across angiosperms ( Vollbrecht et al, 1991 ; Bharathan et al, 2002 ).…”

“…During compound leaf pattern formation, how the KNOX I or LFY/SGL1-associated morphogenetic activity is directly regulated to ensure a correct leaf pattern is a central question. Recent publications suggest that the class II KNOX genes ( KNOX II ) ( KNAT3 , KNAT4 , and KNAT5 ) confer opposing activities with KNOX I genes to suppress leaflet initiation in the simple leaf developmental program of Arabidopsis ( Furumizu et al, 2015 ; Challa et al, 2021 ). Two important transcription factors were reported as repressors of the SGL1 expression during the pattern formation of the M. truncatula trifoliate leaves.…”

Expanding the Benefits of Tnt1 for the Identification of Dominant Mutations in Polyploid Crops: A Single Allelic Mutation in the MsNAC39 Gene Produces Multifoliated Alfalfa

“…Bioinformatic analysis of the Tnt1 -flanking sequences of the mfl mutant plant and its progeny showed that the mfl mutation colocalized with the MsNAC39 gene in chromosome 3.4 ( Figure 1I ). The NAC protein family is a large group of plant-specific transcriptional factors involved in the control of gene expressions related to leaf development and adaptation to environmental conditions ( Liu et al, 2014 ; Oda-Yamamizo et al, 2016 ; Trupkin et al, 2019 ; Min et al, 2020 ; Challa et al, 2021 ). NAC transcriptional factors contain a highly conserved N-terminal DNA-binding domain and a C-terminal hypervariable domain related to the activation or repression of the transcription of specific target genes ( Yamaguchi-Shinozaki and Shinozaki, 2005 ; Le et al, 2011 ; He et al, 2016 ; Maugarny et al, 2016 ).…”