Silva Fredy A, Guirgis Adel, Thornburg Robert
Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States.
Department of Molecular Biology, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt.
Front Plant Sci. 2018 Jul 30;9:1100. doi: 10.3389/fpls.2018.01100. eCollection 2018.
We have evaluated the floral nectars of nine species from different sections of the genus . These nine species effectively cover the genus. We found that the nectary glands from these different species showed similar developmental regulation with swelling of nectaries during the first half of development and a distinct color change in the nectary gland as development approaches anthesis. When we examined the composition of the nectar from these nine different species we found that they were similar in content. Carbohydrate compositions of these various nectars varied between these species with showing the highest and lowest level of sugars. Based upon the amount of carbohydrates, the nectars fell into two groups. We found that hydrogen peroxide accumulated in the nectars of each of these species. While all species showed the presence of hydrogen peroxide in nectar, the quantitative amounts of hydrogen peroxide which was very high in and , suggesting be a common characteristic in short flower species. We further found that the antioxidant ascorbate accumulated in nectar and β-carotene accumulated in nectaries. β-carotene was most high in nectaries of . We also examined the presence of proteins in the nectars of these species. The protein profile and quantities varied significantly between species, although all species have showed the presence of proteins in their nectars. We performed a limited proteomic analysis of several proteins from these nectars and determined that each of the five abundant proteins examined were identified as Nectarin 1, Nectarin 3, or Nectarin 5. Thus, based upon the results found in numerous species across the genus , we conclude that the mechanisms identified are similar to those mechanisms found in previous studies on ornamental tobacco nectars. Further, these similarities are remarkably conserved, throughout the genus .
我们评估了该属不同组的9个物种的花蜜。这9个物种有效地涵盖了该属。我们发现，这些不同物种的蜜腺在发育上表现出相似的调控，蜜腺在发育的前半期会肿胀，并且随着发育接近花期，蜜腺会有明显的颜色变化。当我们检测这9个不同物种花蜜的成分时，发现它们的含量相似。这些不同花蜜的碳水化合物组成在这些物种之间有所不同，其中[物种名称1]的糖分含量最高，[物种名称2]的糖分含量最低。根据碳水化合物的含量，花蜜可分为两组。我们发现过氧化氢在这些物种的每一种花蜜中都有积累。虽然所有物种的花蜜中都含有过氧化氢，但在[物种名称3]和[物种名称4]中过氧化氢的含量非常高，这表明这可能是短花期物种的一个共同特征。我们进一步发现抗氧化剂抗坏血酸在花蜜中积累，β - 胡萝卜素在蜜腺中积累。在[物种名称5]的蜜腺中β - 胡萝卜素含量最高。我们还检测了这些物种花蜜中蛋白质的存在情况。尽管所有物种的花蜜中都含有蛋白质，但不同物种之间蛋白质的谱图和含量差异显著。我们对这些花蜜中的几种蛋白质进行了有限的蛋白质组学分析，确定所检测的5种丰富蛋白质中的每一种都被鉴定为花蜜蛋白1、花蜜蛋白3或花蜜蛋白5。因此，基于在该属众多物种中发现的结果，我们得出结论，所确定的机制与先前关于观赏烟草花蜜的研究中发现的机制相似。此外，这些相似性在整个属中都得到了显著的保留。
