Identification and expression analysis of genes related to multi-ovary in wheat (Triticum aestivum L.)

Multi-ovary wheat is a unique germplasm with more grains per spike and promising potential for the seed production of hybrid wheat. To understand the genetic mechanism of the multi-ovary characteristic, a set of pre-near isogenic lines (NILs) from BC₄F₃ were initially employed to construct two cDNA libraries of multi-ovary and mono-ovary by suppression subtractive hybridization (SSH), and 125 candidate cDNA sequences were obtained. Using BLASTx screening and functional annotation in the NCBI database, ribosomal proteins, nucleoproteins, elongation factors and tubulins were identified in the multi-ovary library. In addition, small subunits of the ribulose-1,5-bisphosphate carboxylase/oxygenase, calcium binding proteins, cysteine proteinase inhibitor and light-harvesting chlorophyll a/b protein precursor were detected in a mono-ovary cDNA library. The expression patterns of 12 genes were analyzed by RT-PCR. There were eight genes showing significant differential expression between multi-ovary and mono-ovary lines. Based on the temporal-spatial expression patterns, the candidate genes were significantly up-regulated at the 1∼12mm developmental stages of ears, and most of the genes were expressed more in the stem shoot meristem than in other tissues. This illustrated that genes differentially expressed in multi-ovary and mono-ovary lines may participate in diverse biochemical and physiological processes that might be responsible for the formation of the multi-ovary characteristic.