Characterization of temperature-sensitive mutants reveals a role for receptor-like kinase SCRAMBLED/STRUBBELIG in coordinating cell proliferation and differentiation during Arabidopsis leaf development.
The balance between cell proliferation and cell differentiation is essential for leaf patterning. However, identification of the factors coordinating leaf patterning and cell growth behavior is challenging. Here, we characterized a temperature-sensitive Arabidopsis mutant with leaf blade and venation defects. We mapped the mutation to the sub-2 allele of the SCRAMBLED/STRUBBELIG (SCM/SUB) receptor-like kinase gene whose functions in leaf development have not been demonstrated. The sub-2 mutant displayed impaired blade development, asymmetric leaf shape and altered venation patterning under high ambient temperature (30°C), but these defects were less pronounced at normal growth temperature (22°C). Loss of SCM/SUB function results in reduced cell proliferation and abnormal cell expansion, as well as altered auxin patterning. SCM/SUB is initially expressed throughout leaf primordia and becomes restricted to the vascular cells, coinciding with its roles in early leaf patterning and venation formation. Furthermore, constitutive expression of the SCM/SUB gene also restricts organ growth by inhibiting the transition from cell proliferation to expansion. We propose the existence of a SCM/SUB-mediated developmental stage-specific signal for leaf patterning, and highlight the importance of the balance between cell proliferation and differentiation for leaf morphogenesis.
National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
Lin
L
Lin
Si-Hui
SH
Zhong
Xiao-Feng
XF
Cui
Jianming
J
Li
Zu-Hua
ZH
He
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D019521:Body Patterning; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D009154:Mutation; D018515:Plant Leaves / Q000166:cytology* / Q000235:genetics / Q000254:growth & development*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013696:Temperature
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D020794:Receptor Protein-Tyrosine Kinases; C503317:SUB protein, Arabidopsis