Pereira Lara, Pujol Marta, Garcia-Mas Jordi, Phillips Michael A
IRTA, Center for Research in Agricultural Genomics (IRTA- CSIC- UAB-UB), Edifici CRAG, Bellaterra, Barcelona, 08193, Spain.
Department of Biology, University of Toronto-Mississauga, Mississauga, ON, L5L 1C6, Canada.
Plant J. 2017 Jul;91(1):172-183. doi: 10.1111/tpj.13545. Epub 2017 May 5.
Ethylene is a gaseous plant hormone involved in defense, adaptations to environmental stress and fruit ripening. Its relevance to the latter makes its detection highly useful for physiologists interested in the onset of ripening. Produced as a sharp peak during the respiratory burst, ethylene is biologically active at tens of nl L . Reliable quantification at such concentrations generally requires specialized instrumentation. Here we present a rapid, high-sensitivity method for detecting ethylene in attached fruit using a conventional gas chromatography-mass spectrometry (GC-MS) system and in situ headspace collection chambers. We apply this method to melon (Cucumis melo L.), a unique species consisting of climacteric and non-climacteric varieties, with a high variation in the climacteric phenotype among climacteric types. Using a population of recombinant inbred lines (RILs) derived from highly climacteric ('Védrantais', cantalupensis type) and non-climacteric ('Piel de Sapo', inodorus type) parental lines, we observed a significant variation for the intensity, onset and duration of the ethylene burst during fruit ripening. Our method does not require concentration, sampling times over 1 h or fruit harvest. We achieved a limit of detection of 0.41 ± 0.04 nl L and a limit of quantification of 1.37 ± 0.13 nl L with an analysis time per sample of 2.6 min. Validation of the analytical method indicated that linearity (>98%), precision (coefficient of variation ≤2%) and sensitivity compared favorably with dedicated optical sensors. This study adds to evidence of the characteristic climacteric ethylene burst as a complex trait whose intensity in our RIL population lies along a continuum in addition to two extremes.
乙烯是一种气态植物激素，参与防御、对环境胁迫的适应以及果实成熟过程。它与果实成熟的相关性使得对其进行检测对于关注成熟起始的生理学家非常有用。乙烯在呼吸跃变期间以尖峰形式产生，在数十纳升/升的浓度下具有生物活性。在如此低的浓度下进行可靠的定量通常需要专门的仪器。在此，我们介绍一种使用常规气相色谱 - 质谱联用（GC - MS）系统和原位顶空收集室检测附着果实中乙烯的快速、高灵敏度方法。我们将此方法应用于甜瓜（Cucumis melo L.），这是一个独特的物种，由跃变型和非跃变型品种组成，跃变型品种在跃变表型上存在很大差异。利用源自高度跃变的亲本系（“Védrantais”，卡塔卢佩尼斯类型）和非跃变的亲本系（“Piel de Sapo”，伊诺多鲁斯类型）的重组自交系群体，我们观察到果实成熟期间乙烯跃变的强度、起始时间和持续时间存在显著差异。我们的方法不需要浓缩、超过1小时的采样时间或果实采摘。我们实现了0.41±0.04纳升/升的检测限和1.37±0.13纳升/升的定量限，每个样品的分析时间为2.6分钟。分析方法的验证表明，其线性度（>98%）、精密度（变异系数≤2%）和灵敏度与专用光学传感器相比具有优势。这项研究进一步证明了特征性的跃变期乙烯释放是一种复杂性状，在我们的重组自交系群体中，其强度除了两个极端情况外，还呈连续变化。
