The Polar Auxin Transport InhibitorN-1-Naphthylphthalamic Acid Disrupts Leaf Initiation, KNOX Protein Regulation, and Formation of Leaf Margins in Maize

• DOI: 10.1104/pp.103.026880
• Publication Date: 2003-10-11T23:57:45Z
• Authors: Michael J. Scanlon
• Keywords: Polar auxin transport; Primordium; Lycopersicon

Abstract Maize (Zea mays) leaves develop basipetally (tip to base); the upper blade emerges from shoot apical meristem (SAM) before expansion of lower sheath. Founder cells, leaf initials located in periphery SAM, are distinguished SAM proper by differential accumulation KNOX proteins. proteins accumulate but excluded maize primordia and founder cells. As Arabidopsis tomato (Lycopersicon esculentum), shoots failed initiate new when cultured polar auxin transport inhibitor N-1-naphthylphthalamic acid (NPA). We demonstrate that NPA-induced arrest initiation is correlated with failure down-regulate SAM. In addition, NPA-cultured formed abnormal tubular bases which margins separate zone. The always fourth arrested meristem. Moreover, unseparated margin domains these accumulated ectopic protein(s). Transfer apices NPA-free media resulted resumption restoration normal patterns down-regulation, accordingly. These data suggest sheath emerge base late development separation down-regulation results not upstream transport, although a more complicated feedback network may exist. A model for L1-derived presented.