Phytohormonal Networks Promote Differentiation of Fiber Initials on Pre-Anthesis Cotton Ovules Grown in Vitro and in Planta

Thursday, January 7, 2016: 8:00 AM
Preservation Hall Studios 7 & 8 (New Orleans Marriott)
Hee Jin Kim , USDA-ARS, Southern Regional Research Center
Doug J Hinchliffe , Cotton Chemistry and Utilization Research Unit, USDA ARS
Barbara Triplett , USDA
Jeffrey Z. Chen , The University of Texas at Austin
David Stelly , Texas A&M University
Kathleen Yeater , USDA-ARS
Hong S. Moon , USDA-ARS
Matthew K Gilbert , USDA-ARS
Gregory N Thyssen , Cotton Chemistry and Utilization Research Unit, USDA ARS
Rickie B Turley , Crop Genetics Research Unit, USDA ARS
David D Fang , Cotton Fiber Bioscience Unit, USDA ARS
How and when fiber initiation occurs on cotton ovules is an important question for biologists, cotton producers, and textile industry since the density and numbers of fibers on the surface of cotton ovules directly affect cotton yield and fiber quality.  Despite its importance, molecular mechanisms regulating cotton fiber initiation are mostly unknown due to technical difficulties in monitoring the rapid process of fiber initial differentiation in cotton ovaries. To understand molecular mechanisms affecting fiber initiation process, we optimized culture conditions for controlling the timing of fiber initiation process on the surface of cotton ovules grown in Petri dishes. With the controlled conditions, we enabled to identify candidate genes involved in fiber initiation process. Those candidate genes were verified with wild type cotton and three fiberless mutants grown in the field.  Various plant hormones and their signaling networks regulated the expression of genes responsible for fiber initiation process. The results provide an insight on molecular mechanisms controlling when and how fiber initiation occurs on cotton ovules. Thus, the ability to manipulate the expression of genes regulating fiber initiation process may lead to strategies for improving cotton yield and fiber quality.