Abstract:
Cotton fiber development is a fundamental
biological phenomenon, yet the molecular basis of fiber
cell initiation is poorly understood. We examined
molecular and cellular events of fiber cell development in
the naked seed mutant (N1N1) and its isogenic line of
cotton (Gossypium hirsutum L. cv. Texas Marker-1,
TM-1). The dominant mutation not only delayed the
process of fiber cell formation and elongation but also
reduced the total number of fiber cells, resulting in
sparsely distributed short fibers. Gene expression changes in TM-1 and N1N1 mutant lines among four tissues
were analyzed using spotted cotton oligo-gene microarrays. Using the Arabidopsis genes, we selected and
designed 1,334 70-mer oligos from a subset of cotton
fiber ESTs. Statistical analysis of the microarray data
indicates that the number of significantly differentially
expressed genes was 856 in the leaves compared to the
ovules (3 days post-anthesis, DPA), 632 in the petals
relative to the ovules (3 DPA), and 91 in the ovules at
0 DPA compared to 3 DPA, all in TM-1. Moreover, 117
and 30 genes were expressed significantly different in the
ovules at three and 0 DPA, respectively, between TM-1
and N1N1. Quantitative RT-PCR analysis of 23 fiberassociated genes in seven tissues including ovules,
fiber-bearing ovules, fibers, and non-fiber tissues in
TM-1 and N1N1 indicates a mode of temporal regulation of the genes involved in transcriptional and translational regulation, signal transduction, and cell
differentiation during early stages of fiber development.
Suppression of the fiber-associated genes in the mutant
may suggest that the N1N1 mutation disrupts temporal
regulation of gene expression, leading to a defective
process of fiber cell elongation and development.Cotton fiber development is a fundamental
biological phenomenon, yet the molecular basis of fiber
cell initiation is poorly understood. We examined
molecular and cellular events of fiber cell development in
the naked seed mutant (N1N1) and its isogenic line of
cotton (Gossypium hirsutum L. cv. Texas Marker-1,
TM-1). The dominant mutation not only delayed the
process of fiber cell formation and elongation but also
reduced the total number of fiber cells, resulting in
sparsely distributed short fibers. Gene expression changes in TM-1 and N1N1 mutant lines among four tissues
were analyzed using spotted cotton oligo-gene microarrays. Using the Arabidopsis genes, we selected and
designed 1,334 70-mer oligos from a subset of cotton
fiber ESTs. Statistical analysis of the microarray data
indicates that the number of significantly differentially
expressed genes was 856 in the leaves compared to the
ovules (3 days post-anthesis, DPA), 632 in the petals
relative to the ovules (3 DPA), and 91 in the ovules at
0 DPA compared to 3 DPA, all in TM-1. Moreover, 117
and 30 genes were expressed significantly different in the
ovules at three and 0 DPA, respectively, between TM-1
and N1N1. Quantitative RT-PCR analysis of 23 fiberassociated genes in seven tissues including ovules,
fiber-bearing ovules, fibers, and non-fiber tissues in
TM-1 and N1N1 indicates a mode of temporal regulation of the genes involved in transcriptional and translational regulation, signal transduction, and cell
differentiation during early stages of fiber development.
Suppression of the fiber-associated genes in the mutant
may suggest that the N1N1 mutation disrupts temporal
regulation of gene expression, leading to a defective
process of fiber cell elongation and development.