Arabidopsis PANS1 regulates vegetative phase transitions by modulating the expression of miR156

Abstract

Organ size control of multicellular organisms poses a longstanding biological question that has always fascinated scientist Especially leaf growth by providing the food and renewable energy sources is at the core of plant growth and undoubtedly an important part of human economic activities Here I report a novel Arabidopsis mutant patronus1 (pans1) which reduced cell size and decreased cell number in leaves The development of abaxial trichomes was also delayed in pans1 These facts indicate that pans1 mutant may accelerate heteroblasty a phenomenon in which several traits of leaves change along with phase change by alternating the cell number and size of cells and trichome development The genetic marker of leaf phase change miR156 normally is down regulated in adult leaves but showed up-regulated in pans1 I also discovered PANS1 inhibits miR156 through its specific domains Furthermore miR156 downstream genes SPL3 5 9 and10 had the decrease expression level in pans1 as a result of abnormal excessive miR156 Thus I suggest that PANS1 plays an essential role of regulating vegetative phase change and promoting adult leaves growth in SPL-dependent pathway by inhibiting miR156 expression Keywords: PANS1 phase change heteroblasty leaf development miR156 SPL genes

Date of Award	2015 Feb 11
Original language	English
Supervisor	Hao-Jen Huang (Supervisor)