ARS | Publication request: SOYBEAN AND TOBACCO FLORAL NECTARIES: TWO GLANDS WITH SIMILAR FUNCTIONAL GOALS BUT WITH DIFFERENT INTERNAL STRUCTURES, METABOLISM AND LIFE SPAN

Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 2004
Publication Date: November 4, 2004
Citation: Horner, H.T., Healy, R.A., Thornburg, R.W., Palmer, R.G. 2004. Soybean and tobacco floral nectaries: two glands with similar functional goals but with different internal structures, metabolism and life span. American Society of Agronomy Abstracts. Paper No. 1031.

Technical Abstract: Tobacco nectaries in the basal gynoecium wall are donut-shaped. Soybean nectaries form discard mounds between the base of the gynoecium and the staminal ring. Both nectaries differ in the timing of development and manner of secretion. Our objective was to compare the development of nectaries in tobacco and soybean using in situ hybridization and immunocytochemistry. A number of tobacco genes and proteins have been identified and sequenced during nectary life. Some of them display a high level of amino acid sequence homology with soybean. Tobacco nectarines develop over several days and remain active for sometime. They are not innervated by vasculature, and their parenchyma becomes engorged with starch prior to secretion. Soybean nectaries initiate, secrete, and degenerate over a two-day period. Phloem fingers innervate these nectaries and their parenchyma contains little starch. Spatial and temporal patterns of expression of nectarin genes (via mRNA) and proteins show similarities and major differences between soybean and tobacco. Attempts are being made to relate these changes to pollinator attraction in soybean.