Pengaruh Arah Distribusi Auksin terhadap Pola Pembentukan Primordium Daun pada Arabidopsis

This literature review synthesizes a wide range of research findings that examine the role of auxin distribution direction in regulating leaf primordium patterning, known as phyllotaxis, in Arabidopsis thaliana. The reviewed studies consistently indicate that phyllotaxis represents a highly coordinated growth regulation mechanism that is primarily governed by Polar Auxin Transport (PAT), which is mediated by Pin-Formed (PIN) auxin efflux proteins. The polarity and spatial localization of PIN proteins generate dynamic auxin gradients within the shoot apical meristem, and these gradients function as key positional signals that determine the precise sites where new leaf primordia are initiated. Furthermore, auxin distribution is not regulated solely by PAT but is tightly integrated with genetic, cellular, and mechanical cues. Several studies highlight the role of transcription factors such as TMO5 in influencing PIN1 convergence and reinforcing auxin maxima at primordium initiation sites. In addition, the interaction between PIN polarity and the orientation of cortical microtubules suggests that mechanical stress and cytoskeletal organization contribute to the stability and directionality of auxin flow. Comparative analysis of the literature demonstrates that PAT and PIN proteins operate through interconnected mechanisms to control auxin distribution direction, which ultimately shapes the spatial arrangement and regularity of leaf primordium patterns. Overall, this review emphasizes the complexity and integration of hormonal, genetic, and mechanical signals in controlling phyllotaxis in plants.