Gene-Specific Changes in α-Tubulin Transcript Accumulation in Developing Cotton Fibers

• Published in: Plant physiology (Bethesda) Vol. 121; no. 1; pp. 181 - 188
• Main Authors: Whittaker, David J., Triplett, Barbara A.
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01-09-1999
• Subjects: 3' Untranslated Regions - genetics; Agronomy. Soil science and plant productions; Amino Acid Sequence; Biological and medical sciences; Cell biochemistry; Cell Differentiation; Cell physiology; Cell Size; Cell Wall - metabolism; Cell walls; Cellulose - metabolism; Classical and quantitative genetics. Population genetics. Molecular genetics; Cloning, Molecular; Complementary DNA; Cotton; Cotton fibers; DNA, Complementary - genetics; Fiber cells; Fundamental and applied biological sciences. Psychology; Gene Expression; Generalities. Genetics. Plant material; Genes; Genes, Plant - genetics; Genetics and breeding of economic plants; Gossypium - cytology; Gossypium - genetics; Gossypium - growth & development; Gossypium - metabolism; Gossypium hirsutum; Growth and Development; Microtubules; Microtubules - metabolism; Molecular genetics; Molecular Sequence Data; Plant cells; Plant physiology and development; Plant Structures - genetics; Plants; Polymerase Chain Reaction; Protein Isoforms - genetics; RNA; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Plant - genetics; RNA, Plant - metabolism; Sequence Alignment; Space life sciences; Time Factors; Tubulin - genetics; Tubulin - metabolism; Malvaceae; Molecular structure; Growth; Tissue specificity; Fiber crop; Time variation; Cell wall; Messenger RNA; Tubulin; Dicotyledones; Angiospermae; Spermatophyta; Gossypium hirsutum; Biological accumulation; Cotton fiber; Elongation; Non-programmatic
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.121.1.181

The fibers of cotton (Gossypium hirsutum) are single-cell trichomes that undergo rapid and synchronous elongation. Cortical microtubules provide spatial information necessary for the alignment of cellulose microfibrils that confine and regulate cell elongation. We used gene-specific probes to investigate α-tubulin transcript levels in elongating cotton fibers. Two discrete patterns of transcript accumulation were observed. Whereas transcripts of α-tubulin genes GhTua2/3 and GhTua4 increased in abundance from 10 to 20 d post anthesis (DPA), GhTua1 and GhTua5 transcripts were abundant only through to 14 DPA, and dropped significantly at 16 DPA with the onset of secondary wall synthesis. This is the first report, to our knowledge, of gene-specific changes in tubulin transcript levels during the development of a terminally differentiated plant cell. The decrease in abundance of GhTua1 and GhTua5 transcripts was correlated with pronounced changes in cell wall structure, suggesting that α-tubulin isoforms may be functionally distinct in elongating fiber cells. Although total α-tubulin transcript levels were much higher in fiber than several other tissues, including the hypocotyl and pollen, none of the α-tubulins was specific to fiber cells.