The loss of polyphenol oxidase function is associated with hilum pigmentation and has been selected during pea domestication

第一作者：Jana Balarynová

第一单位：帕拉斯基大学

通讯作者：Petr Smýkal

 Abstarct 

背景回顾：Seed coats serve as protective tissue to the enclosed embryo. Beside mechanical there are also chemical defence functions. During domestication, the property of the seed coat was altered including removal of the seed dormancy. 

种皮是保护胚胎的一种组织。除了机械防御外，种皮还承担了化学防御的功能。在植物的驯化过程中，种皮的性质会发生改变，这些改变过程包括了种子休眠的解除。

结果1-SlNAM3过表达表型：We used a range of genetic, transcriptomic, proteomic and metabolomic approaches to determine the function of pea seed polyphenol oxidase (PPO) gene. 

本文中，作者使用了一系列遗传学、转录组学、蛋白质组学和代谢组学的方法，用以确定豌豆种子中多酚氧化酶PPO编码基因的功能。

结果：Sequencing analysis revealed one nucleotide insertion or deletion in the PPO gene, with the functional PPO allele found in all wild pea samples, while the majority of cultivated peas have one of the three non-functional ppo alleles. PPO functionality co-segregates with hilum pigmentation. PPO gene and protein expression, as well as enzymatic activity, were down regulated in the seed coats of cultivated peas. The functionality of the PPO gene relates to the oxidation and polymerization of gallocatechin in the seed coat. Additionally, imaging mass spectrometry supports the hypothesis that hilum pigmentation is conditioned by the presence of both phenolic precursors and sufficient PPO activity.

测序分析显示，PPO基因中有一个核苷酸插入或缺失，所有的野生豌豆样品中都存在1个功能性的PPO等位基因；相反，大多数栽培种豌豆中包含3种非功能性PPO等位基因中的1种。PPO的功能性与脐点位置的色素沉着共分离。在栽培种豌豆的种皮中，PPO基因的表达和其编码蛋白的酶活均有所下调。PPO基因的功能与种皮中没食子儿茶素的氧化和聚合有关。此外，质谱分析的结果表明，植物脐点处的色素沉着是由酚类前体的存在以及足够的PPO活性所调节的。

结论：Taken together these results indicate that non-functional polyphenol oxidase gene has been selected during pea domestication, possibly due to better seed palatability or seed coat visual appearance.

综上，本文的研究结果表明在豌豆驯化过程中，非功能性多酚氧化酶基因受到了选择，这可能作用于豌豆种子的适口性或者种皮外观。

** Petr Smýkal **

doi: https://doi.org/10.1111/nph.18256

Journal: New Phytologist

First Published: May 18, 2022

CITE

Jana Balarynová, Barbora Klčová, Jana Sekaninová, Lucie Kobrlová, Monika Zajacová Cechová, Petra Krejčí, Tatiana Leonova, Daria Gorbach, Christian Ihling, Lucie Smržová, Oldřich Trněný, Andrej Frolov, Petr Bednář, Petr Smýkal. The loss of polyphenol oxidase function is associated with hilum pigmentation and has been selected during pea domestication. New Phytologist, 2022. DOI: https://doi.org/10.1111/nph.18256