Lubini Greice, Ferreira Pedro Boscariol, Quiapim Andréa Carla, Brito Michael Santos, Cossalter Viviane, Pranchevicius Maria Cristina S, Goldman Maria Helena S
Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, SP, Brazil.
PPG-Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14049-900, SP, Brazil.
Plants (Basel). 2023 Jan 10;12(2):329. doi: 10.3390/plants12020329.
Successful plant reproduction and fruit formation depend on adequate pollen and pistil development, and pollen-pistil interactions. In , pollen tubes grow through the intercellular spaces of pistil-specialized tissues, stigmatic secretory zone, and stylar transmitting tissue (STT). These intercellular spaces are supposed to be formed by the modulation of cell wall pectin esterification. Previously we have identified a gene preferentially expressed in pistils encoding a putative pectin acetylesterase (PAE), named . Here, we characterized the gene and performed genome-wide and phylogenetic analyses of PAEs. We identified 30 PAE sequences in the genome, distributed in four clades. The expression of was assessed by RT-qPCR and hybridization. We confirmed preferential expression in stigmas/styles and ovaries and demonstrated its high expression in the STT. Structural predictions and comparisons between NtPAE1 and functional enzymes validated its identity as a PAE. Transgenic plants were produced, overexpressing and silencing the gene. Overexpressed plants displayed smaller flowers while silencing plants exhibited collapsed pollen grains, which hardly germinate. silencing plants do not produce fruits, due to impaired pollen tube growth in their STTs. Thus, NtPAE1 is an essential enzyme regulating pectin modifications in flowers and, ultimately, in plant reproduction.
成功的植物繁殖和果实形成依赖于充足的花粉和雌蕊发育以及花粉与雌蕊的相互作用。在植物中，花粉管通过雌蕊特化组织、柱头分泌区和花柱传递组织（STT）的细胞间隙生长。这些细胞间隙被认为是由细胞壁果胶酯化的调节形成的。此前我们已经鉴定出一个在雌蕊中优先表达的基因，该基因编码一种假定的果胶乙酰酯酶（PAE），命名为 。在这里，我们对该基因进行了表征，并对PAE进行了全基因组和系统发育分析。我们在基因组中鉴定出30个PAE序列，分布在四个进化枝中。通过RT-qPCR和杂交评估了 的表达。我们证实了其在柱头/花柱和卵巢中的优先表达，并证明其在STT中高表达。NtPAE1与功能酶之间的结构预测和比较验证了其作为PAE的身份。我们培育了过表达和沉默该基因的转基因植物。过表达的植物花朵较小，而沉默的植物表现出花粉粒塌陷，几乎不能萌发。由于其STT中的花粉管生长受损，沉默植物不结果实。因此，NtPAE1是一种调节花中果胶修饰并最终调节植物繁殖的必需酶。
