气调贮藏条件下脱落酸及其代谢产物对绿芦笋衰老过程的影响

Investigating the role of abscisic acid and its catabolites on senescence processes in green asparagus under controlled atmosphere (CA) storage regimes

气调贮藏条件下脱落酸及其代谢产物对绿芦笋衰老过程的影响

Maria Anastasiadia,¹, Emma R. Collingsa,^b,1, Leon A. Terrya,*

^aPlant Science Laboratory, Cranfield University, Bedfordshire MK43 0AL, UK

^bCobrey Farms Ross-on-Wye, Herefordshire HR9 5SG, UK

Received 2 December 2021, Revised 24 February 2022, Accepted 25 February 2022, Available online 14 March 2022, Version of Record 14 March 2022.

https://doi.org/10.1016/j.postharvbio.2022.111892

Highlights
•ABA and PA were associated with accelerated senescence processes in asparagus.
•CA extended asparagus storage life by suppressing ABA and ABA catabolite accumulation.
•Low O2 and high CO2 helped maintain higher sugar content compared to control.
•LabPods™ enabled real-time monitoring of asparagus metabolic rates.

•ABA 和 PA 与芦笋的加速衰老过程有关。
•CA 通过抑制 ABA 和 ABA 分解代谢物的积累来延长芦笋的储存寿命。
•与对照相比，低 O ₂和高 CO ₂有助于保持较高的糖含量。
•LabPods™ 能够实时监测芦笋代谢率。

ABSTRACT

Asparagus (Asparagus officinalis) is a highly perishable crop with a short postharvest life. Although some research has been done on the application of controlled atmosphere (CA), it has not been sufficiently explored and the underlying mechanisms controlling asparagus senescence processes are not well understood, restricting its po-tential for commercial application. The aim of this study was to investigate for the first time the link between abscisic acid (ABA) and ABA catabolites and senescence in asparagus stored under a range of different CA conditions. Two different set-ups were run in parallel; a traditional CA delivered by an International Controlled Atmosphere (ICA) system with continuous gas supply and LabPods™ fitted with sensors for real time monitoring of respiration rate (RR) and respiratory quotient (RQ) and able to retain established CA conditions with mini-mum gas supply requirements. The role of genetic variability was also studied by including two UK grown asparagus cultivars ‘Gijnlim’ and ‘Jaleo’ adapted for different climatic conditions. The results indicated that ABA and its catabolites were present in significantly higher concentrations in the air stored spears (control) compared to CA throughout storage, irrespective of cultivar, and were associated with accelerated senescence processes observed in control samples, such as textural changes indicative of spear toughening, discolouration, sugar depletion and asparagine accumulation. Furthermore, partial least squares regression (pls-r) applied for both cultivars, successfully differentiated samples based on O2 and CO2 concentrations and storage duration, both in cold storage and during shelf-life with the separation being driven primarily by ABA and its catabolites. Phys-iological and biochemical results indicated that all three CA conditions tested ([CA1] 2.5% O2, 3% CO2, [CA2] 2.5% O2, 6% CO2 and [CA3] 2.5% O2, 10% CO2) successfully retained quality parameters including texture, colour, moisture content and visual appearance longer compared to air (control); however, they did not completely suppress the development of ‘tip-breakdown’ (a physiological disorder also known as tip rot) towards the end of storage, which coincided with rising concentrations of phaseic acid indicating an activation of the abscisic biosynthetic and catabolic pathway. It can be concluded that CA conditions can delay senescence for at least 3-weeks (2 weeks cold storage and 1 week shelf-life), by lowering metabolic rate and respiratory quotient (RQ) within the spears compared to control, and through successfully regulating ABA biosynthetic and catabolic pathways.

芦笋是一种极易腐烂的作物，采后寿命短。尽管人们已经对气调贮藏（CA）的应用进行了一些研究，但还没有对其进行充分的探索，对控制芦笋衰老过程的潜在机制也没有很好的了解，这限制了其商业应用的潜力。本研究的目的是首次研究在不同气调条件下贮藏的芦笋中脱落酸（ABA）和ABA分解代谢与衰老之间的关系。两种不同的设置并行运行；传统的CA由国际气调（ICA）系统提供，具有连续供气和LabPods™ 配有实时监测呼吸率（RR）和呼吸商（RQ）的传感器，能够在最小供气要求下保持既定的CA条件。通过将两个适应不同气候条件的英国栽培芦笋品种“Gijnlim”和“Jaleo”纳入研究，还研究了遗传变异的作用。结果表明，在整个贮藏过程中，无论品种如何，空气贮藏芦笋（对照组）中ABA及其分解代谢产物的浓度均显著高于CA，并且与对照组样品中观察到的加速衰老过程有关，如表明芦笋韧化、变色、老化的结构变化，糖分消耗和天冬酰胺积累。此外，偏最小二乘回归（PLS-R）应用于这两个品种，成功地根据O₂和CO₂浓度以及冷藏和货架期的贮藏时间区分了样品，分离主要由ABA及其分解代谢产物驱动。物理、生物和生化结果表明，与空气（对照组）相比，所有三种CA气调测试条件（[CA1]2.5%O₂，3%CO₂，[CA2]2.5%O₂，6%CO₂和[CA3]2.5%O₂，10%CO₂）成功地保留了包括质地、颜色、水分含量和视觉外观在内的质量参数；然而，它们并没有完全抑制贮藏末期“叶尖分解”（一种生理性疾病，也被称为叶尖腐烂）的发展，这与三羧酸浓度的升高相一致，表明脱落生物合成和分解代谢途径的激活。可以得出结论，与对照组相比，CA气调条件可以通过降低芽叉内的代谢率和呼吸商（RQ），并通过成功调节ABA生物合成和分解代谢途径，延缓衰老至少3周（冷藏2周，保质期1周）。

Keywords：Asparagus officinalis，Abscisic acid (ABA)，Sugars， ABA catabolites

关键词：芦笋，脱落酸 (ABA)，糖，ABA 分解代谢物

···

2.2. Real time RR and RQ monitoring using Labpods

As stated in Section 2.1., a sub sample of spears from year 1 were randomly divided into LabPods™ (Storage Control Systems Ltd, Kent UK) with the aim to study the influence of CA conditions on asparagus metabolic rates in real-time. Due to the limited number of LabPods™ available, only CA2 and control were assessed within LabPods™ with two assigned to each treatment. Each LabPod™ was filled with ca. 21 Kg of asparagus spears equally distributed into three plastic crates. The setup for LabPods™ is depicted in picture S2.

LabPods™ remained undisturbed for the duration of cold storage (4 weeks) replicating a commercial scenario. Ultrasonic humidifiers maintained a high RH inside each LabPod™. Gas concentrations were monitored automatically every hour and adjusted accordingly. In addition, RR and RQ measurements were automatically recorded every 48 h by the LabPod™ system. Once opened, spears were randomly selected for physiological and biochemical analysis, alongside additional spears for shelf-life assessment (in air at 7 °C for up to 7 days in light, as previously described by Anastasiadi et al., 2020).

如第 2.1 节所述，将第 1年的芦笋样本随机分为 LabPods™（Storage Control Systems Ltd, Kent UK），旨在实时研究 CA 条件对芦笋代谢率的影响。由于可用的 LabPods™ 数量有限，因此在 LabPods™ 中仅评估了 CA2 和对照，每种处理分配了两个。每个 LabPod™ 都充满了大约. 将 21 公斤芦笋平均分配到三个呼吸室中。LabPods™ 的设置如图S2所示。

LabPods™ 在复制商业场景的冷藏期间（4 周）保持不受干扰。超声波加湿器在每个 LabPod™ 内保持高 RH。每小时自动监测气体浓度并进行相应调整。此外，LabPod™ 系统每 48 小时自动记录RR 和RQ测量值。一旦打开，就会随机选择芦笋进行生理和生化分析，同时选择额外的芦笋进行保质期评估（在 7 °C 的空气中光照长达 7 天，如Anastasiadi 等人先前所述，2020 年）

Fig. 2. Effect of two CA (CA1: 2.5 kPa O2 + 3 kPa CO2; CA2 – 2.5 kPa O2 + 6 kPa CO2) treatments compared to control (air) on asparagine content (g kg−1 DW) in asparagus (‘Gijnlim’) during Exp. 1 cold storage (CS) within boxes and after shelf-life (SL) (day 34). Multiple standard error bars are shown. Different letters denote significant differences.

与对照（空气）相比，两种 CA（CA1：2.5 kPa O 2 + 3 kPa CO 2；CA2 – 2.5 kPa O 2 + 6 kPa CO 2 ）处理对芦笋中天冬酰胺含量（g kg -1 DW）的影响（' Gijnlim') 在 Exp. 1 盒内冷藏 (CS) 和保质期后 (SL)（第 34 天）。显示了多个标准误差条。不同字母表示显着差异。

···

5. Conclusions

In the present study we demonstrated that low oxygen and high CO2 conditions significantly suppressed ABA and asparagine levels in asparagus during storage, coinciding with lower metabolic rates, higher sugars and more vibrant colour compared to control samples, thereby helping maintain asparagus quality for at least 2 weeks of cold storage followed by 7 days of shelf-life. The study revealed for the first time the influence of ABA and its catabolites on senescence processes in asparagus and could guide future efforts to further improve storage conditions and extend shelf-life. In addition, real-time monitoring of asparagus metabolic rates using LabPods™ could provide an early warning system for abiotic stress to better inform industry on “use-by” dates.

在本研究中，我们证明了低氧和高二氧化碳条件显著抑制了芦笋在贮藏期间的ABA和天冬酰胺水平，与对照样品相比，代谢率更低，糖分更高，颜色更鲜艳，从而有助于在冷藏至少2周后保持芦笋的质量，然后保持7天的保质期。这项研究首次揭示了ABA及其分解代谢产物对芦笋衰老过程的影响，并可能指导未来进一步改善贮藏条件和延长保质期的努力。此外，使用LabPods™实时监测芦笋的代谢率 可以为非生物压力提供早期预警系统，以便更好地告知行业“使用日期”。

原文链接：https://www.sciencedirect.com/science/article/pii/S0925521422000606

*本文内容非商业广告，仅供专业人士参考!