KN1achtige

KN1achtige, or KN1-like in Dutch, refers to a group of genes that encode KNOTTED1-like homeobox (KNOX) transcription factors in plants. The KN1 gene was first identified in maize and gave the name to this family; KN1-like genes are now known from a wide range of plant species. They are plant-specific regulators that play key roles in shoot apical meristem function and overall plant architecture.

KNOX proteins are characterized by a homeodomain that binds DNA and typically function as part of transcriptional complexes, often partnering with BEL1-like (BEL) homeodomain proteins to regulate target genes in the nucleus. The KN1-like family is usually divided into two major classes: Class I and Class II. Class I KN1-like genes are mainly expressed in the shoot apical meristem and early leaf primordia and are associated with sustaining meristem indeterminacy. Class II genes have more varied expression patterns and are frequently involved in modulating leaf development and maturation or other developmental processes.

Functions and effects: KN1-like genes regulate hormonal pathways that influence growth, notably promoting cytokinin signaling while repressing gibberellin biosynthesis in many species. This hormonal balance supports the maintenance of undifferentiated meristematic tissue and shapes organ development. Misexpression of KN1-like genes can lead to changes in leaf morphology, altered meristem activity, or abnormal plant architecture.

Evolution and relevance: The KN1-like family is conserved across land plants, with gene duplications contributing to morphological diversity. In agriculture and plant breeding, manipulation of KN1-like gene activity offers a potential approach to modify plant architecture and growth patterns, with implications for yield and adaptation.