Functional characterization of Gossypium hirsutum profilin 1 gene (GhPFN1) in tobacco suspension cells. Characterization of in vivo functions of a cotton profilin gene.
Cotton fiber is an extremely long plant cell. Fiber elongation is a complex process and the genes that are crucial for elongation are largely unknown. We previously cloned a cDNA encoding an isoform of cotton profilin and found that the gene (designated GhPFN1) was preferentially expressed in cotton fibers. In the present study, we have further analyzed the expression pattern of GhPFN1 during fiber development and studied its cellular function using tobacco suspension cells as an experimental system. We report that expression of GhPFN1 is tightly associated with fast elongation of cotton fibers whose growth requires an intact actin cytoskeleton. Overexpression of GhPFN1 in the transgenic tobacco cells was correlated with the formation of elongated cells that contained thicker and longer microfilament cables. Quantitative analyses revealed a 2.5-3.6 fold increase in total profilin levels and a 1.6-2.6 fold increase in the F-actin levels in six independent transgenic lines. In addition to the effect on cell elongation, we also observed delayed cell cycle progression and a slightly lower mitotic index in the transgenic cells. Based on these data, we propose that GhPFN1 may play a critical role in the rapid elongation of cotton fibers by promoting actin polymerization.
National Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100080, China.
Hai-Yun
HY
Wang
Yi
Y
Yu
Zhi-Ling
ZL
Chen
Gui-Xian
GX
Xia
D008841:Actin Cytoskeleton / Q000502:physiology / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D049108:Cell Enlargement; D048430:Cell Shape / Q000502:physiology; D002478:Cells, Cultured; D003368:Gossypium / Q000235:genetics*; D007399:Interphase / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000378:metabolism; D051304:Profilins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology / Q000235:genetics*
D000199:Actins; D010940:Plant Proteins; D051304:Profilins; D012333:RNA, Messenger