Distinct palisade tissue development processes promoted by leaf autonomous signalling and long‐distance signalling in Arabidopsis thaliana

• Published in: Plant, cell and environment cell and environment, 2015-06, Vol.38 (6), p.1116-1126
• Main Authors: MUNEKAGE, YURI NAKAJIMA, INOUE, SHIO, YONEDA, YUKI, YOKOTA, AKIHO
• Format: Article
• Language: English
• Subjects: acclimation; Arabidopsis - growth & development; Arabidopsis - physiology; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; blue light; Cell Count; gene expression; Gene Expression Regulation, Plant - physiology; genes; hydrogen peroxide; Hydrogen Peroxide - pharmacology; leaves; Light; lighting; long‐distance signalling; mesophyll; oxidative stress; palisade tissue; phototropin; Phototropins - physiology; Plant Leaves - cytology; Plant Leaves - drug effects; Plant Leaves - growth & development; Plant Leaves - physiology; Real-Time Polymerase Chain Reaction; signal transduction; Signal Transduction - physiology; transcription factors; ZAT10; ZAT12
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.12466

Plants develop palisade tissue consisting of cylindrical mesophyll cells located at the adaxial side of leaves in response to high light. To understand high light signalling in palisade tissue development, we investigated leaf autonomous and long‐distance signal responses of palisade tissue development using Arabidopsis thaliana. Illumination of a developing leaf with high light induced cell height elongation, whereas illumination of mature leaves with high light increased cell density and suppressed cell width expansion in palisade tissue of new leaves. Examination using phototropin1 phototropin2 showed that blue light signalling mediated by phototropins was involved in cell height elongation of the leaf autonomous response rather than the cell density increase induced by long‐distance signalling. Hydrogen peroxide treatment induced cylindrical palisade tissue cell formation in both a leaf autonomous and long‐distance manner, suggesting involvement of oxidative signals. Although constitutive expression of transcription factors involved in systemic‐acquired acclimation to excess light, ZAT10 and ZAT12, induced cylindrical palisade tissue cell formation, knockout of these genes did not affect cylindrical palisade tissue cell formation. We conclude that two distinct signalling pathways – leaf autonomous signalling mostly dependent on blue light signalling and long‐distance signalling from mature leaves that sense high light and oxidative stress – control palisade tissue development in A. thaliana.