A leucine-rich repeat receptor-like kinase gene is involved in the specification of outer cell layers in rice roots.
Root outer cell layers of Oryza sativa (rice), which comprise the epidermis, exodermis and sclerenchyma, play an important role in protecting the roots from various stresses in soil, but the molecular mechanisms for the specification of these cell layers are poorly understood. In this work, we report on defective in outer cell layer specification 1 (Docs1), which is involved in the specification of outer cell layers in rice roots. Docs1 was isolated by map-based cloning using a mutant (c68) defective in the outer cell layers of primary roots. It encodes a leucine-rich repeat receptor-like kinase (LRR RLK). Docs1 mRNA was expressed in all tissues including roots, leaf blades and sheaths, and flowers. Immunostaining with an anti-Docs1 antibody showed that Docs1 was localized at the epidermis and exodermis, depending on the root region. Furthermore, Docs1 showed polar localization at the distal side. Subcellular examination showed that Docs1 was localized to the plasma membrane. Comparison of genome-wide transcriptional profiles between the wild-type and the knock-out mutant roots using microarray analysis showed that 61 and 41 genes were up- and downregulated in the mutant, including genes encoding putative transcription factors and genes potentially involved in cell wall metabolism. These results suggest that Docs1 might directly or indirectly regulate multiple genes involved in the proper development of root outer cell layers in rice.
Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki 710-0046, Japan.
Chao-Feng
CF
Huang
Naoki
N
Yamaji
Kazuko
K
Ono
Jian Feng
JF
Ma
D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000201:enzymology; D002874:Chromosome Mapping; D015536:Down-Regulation; D035264:Flowers / Q000033:anatomy & histology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000033:anatomy & histology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D010802:Phylogeny; D019441:Plant Epidermis / Q000033:anatomy & histology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D018515:Plant Leaves / Q000033:anatomy & histology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics; D015854:Up-Regulation
D010940:Plant Proteins; D012333:RNA, Messenger; D011494:Protein Kinases