Joly Valentin, Tebbji Faïza, Nantel André, Matton Daniel P
Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, QC H1X 2B2, Canada.
CRCHU de Québec, Université Laval, Québec, QC G1V 4G2, Canada.
Plants (Basel). 2019 Jun 24;8(6):185. doi: 10.3390/plants8060185.
Sexual reproduction in flowering plants involves intimate contact and continuous interactions between the growing pollen tube and the female reproductive structures. These interactions can trigger responses in distal regions of the flower well ahead of fertilization. While pollination-induced petal senescence has been studied extensively, less is known about how pollination is perceived at a distance in the ovary, and how specific this response is to various pollen genotypes. To address this question, we performed a global transcriptomic analysis in the ovary of a wild potato species, , at various time points following compatible, incompatible, and heterospecific pollinations. In all cases, pollen tube penetration in the stigma was initially perceived as a wounding aggression. Then, as the pollen tubes grew in the style, a growing number of genes became specific to each pollen genotype. Functional classification analyses revealed sharp differences in the response to compatible and heterospecific pollinations. For instance, the former induced reactive oxygen species (ROS)-related genes while the latter affected genes associated to ethylene signaling. In contrast, incompatible pollination remained more akin to a wound response. Our analysis reveals that every pollination type produces a specific molecular signature generating diversified and specific responses at a distance in the ovary in preparation for fertilization.
开花植物的有性生殖涉及生长中的花粉管与雌蕊生殖结构之间的密切接触和持续相互作用。这些相互作用能够在受精之前很早的时候就引发花朵远端区域的反应。虽然授粉诱导的花瓣衰老已得到广泛研究，但对于授粉如何在子房远处被感知，以及这种反应对各种花粉基因型的特异性程度了解较少。为了解决这个问题，我们在一种野生马铃薯物种的子房里，于亲和授粉、不亲和授粉和异源授粉后的不同时间点进行了全转录组分析。在所有情况下，花粉管在柱头上的穿透最初被视为一种创伤性侵害。然后，随着花粉管在花柱中生长，越来越多的基因对每种花粉基因型具有特异性。功能分类分析揭示了对亲和授粉和异源授粉反应的显著差异。例如，前者诱导与活性氧（ROS）相关的基因，而后者影响与乙烯信号传导相关的基因。相比之下，不亲和授粉更类似于创伤反应。我们的分析表明，每种授粉类型都会产生特定的分子特征，在子房远处产生多样化和特异性的反应，为受精做准备。
