NARROW AND DWARF LEAF 1, the Ortholog of Arabidopsis ENHANCER OF SHOOT REGENERATION1/DORNRoSCHEN, Mediates Leaf Development and Maintenance of the Shoot Apical Meristem in Oryza sativa L

The molecular basis for leaf development, a major focus in developmental biology, remains unclear in the monocotyledonous grass, rice (Oryza sativa). Here, we performed a mutant screen in rice and identified an AP2-type transcription factor family protein, NARROW AND DWARF LEAF1 (NDL1). NDL1 is the ortholog of Arabidopsis thaliana (subsequently called Arabidopsis) ENHANCER OF SHOOT REGENERATION1 (ESR1)/DORNRoSCHEN (DRN) and mediates leaf development and maintenance of the shoot apical meristem (SAM). Loss of function of NDL1 results in bladeless leaves and SAMs that are flat, rather than dome-shaped, and lack cell proliferation activity. This loss of function also causes reduced auxin signaling. Moreover, as is the case with Arabidopsis ESR1/DRN, NDL1 plays crucial roles in shoot regeneration. Importantly, we found that NDL1 is not expressed in the SAM but is expressed in leaf primordia. We propose that NDL1 cell autonomously regulates leaf development, but non-cell autonomously regulates SAM maintenance in rice.

Automated summary

NDL1 is a crucial transcription factor in rice that regulates leaf development and shoot apical meristem maintenance. Loss of NDL1 function results in abnormal leaves and shoot apical meristems, as well as reduced auxin signaling. The study reveals the molecular basis for leaf development in rice.