菠萝黑心病机理研究进展

菠萝黑心病是菠萝采后的主要病害之一。黑心病病果通常无明显的外部特征，难以在外观上与正 常果实进行区分。菠萝黑心病的初期症状是果心基部附近出现半透明的小斑点；随着病情的发展，果肉中逐渐 开始出现黑褐色色素沉着，并逐步蔓延整个菠萝果实。近年来，由于滥用赤霉素壮果等原因，过去不易发生黑 心病的菠萝夏果中也可见相关报道，给整个菠萝产业造成了巨大的经济损失。国内外学者已对菠萝黑心病的潜 在机理进行了长期研究，并提出了多种解决方案。因此，总结现有的菠萝黑心病研究进展，对于研究菠萝黑心 病的内在机理，培育抗黑心病品种以及提高菠萝产业的生产效率均具有积极作用。 总结了影响菠萝黑心病发生 的采前与采后因素及其相应对策，并结合相关激素信号通路的研究进展提出了菠萝黑心病发生过程的可能模型。 模型分为 3 个阶段，即初始阶段、细胞凋亡执行阶段和褐变阶段。低温胁迫是菠萝黑心病的主要诱发因素，在 起始阶段起到诱导活性氧产生、损伤质膜的作用；赤霉素信号在低温胁迫信号的下游，即黑心病细胞凋亡执行 阶段发挥着重要作用；而多酚氧化酶在菠萝黑心病褐变阶段催化的褐变反应是一种次级反应，多酚氧化酶的表 达水平与黑心病的发生率并无直接关联性。

Research Progress on Mechanisms of Pineapple Blackheart

Pineapple blackheart is one of the major diseases after harvesting. The damaged fruits usually have no obvious external characteristics and are hard to be distinguished from the normal ones. The initial symptoms of pineapple blackheart are translucent spots appearing near the fruit core. With the development of the internal browning, dark-brown pigmentation begins to appear in the pulp and gradually spreads to the whole fruit. In recent years, due to the abuse of gibberellins or other reasons, blackheart has been reported to appear in summer fruits of pineapples, causing huge economic losses to the whole pineapple industry. Scholars at home and abroad have studied the underlying mechanisms of pineapple and proposed various solutions. Therefore, summary of the current research progresses have positive influence on studying the mechanisms of pineapple blackheart, breeding blackheart resistant cultivars and improving the production efficiency of the pineapple industry. This paper summarized the pre-harvest and post-harvest factors affecting the occurrence of pineapple blackheart and the corresponding countermeasures, and proposed a possible model of pineapple blackheart based on the recent progresses of related hormone signaling pathways. The model can be divided into three stages, namely, initial stage, apoptosis execution stage and browning stage. Chilling stress is a major factor of internal browning, which induces ROS and causes membrane damage in the initial stage of pineapple blackheart. Gibberellins act in the downstream of chilling stress, which play an important role in the apoptosis execution stage. The browning reaction catalyzed by PPO in the browning stage might be only a secondary response. There is no direct correlation between the level of PPO and the incidence of pineapple blackheart.