Microplastics (MPs) have become a ubiquitous emerging pollutant in the global marine environment. The potential toxic effects of MPs and interactions of MP pollution with other stressors such as food limitation on marine organisms’ health are not yet well understood. This study investigated the effects of three-week exposure to different MPs and food shortage on the physical defense mechanisms (byssus production and properties) of Mytilus coruscus. Starvation significantly reduced the number of byssus threads, and combined exposure to MPs and food shortage suppressed the adhesion ability and condition index of mussels. The length of the byssus threads was not affected by all experimental exposures. Transcript levels of genes encoding key proteins involved in byssus formation (the mussel foot proteins mfp-1, -2, -3, -4, -5 and -6, and prepolymerized collagen proteins preCOL-D, -P and -NG) were altered by interactions between the MPs and food shortage. These findings show that insufficient food supply can exacerbate the adverse effects of MPs on mussel defense which might have implications for survival and fitness of mussels under food limited conditions (e.g. in winter) in polluted coastal habitats.

微塑料 (MPs) 已成为全球海洋环境中无处不在的新兴污染物。MP 的潜在毒性作用以及 MP 污染与其他压力因素（如食物限制）对海洋生物健康的相互作用尚不清楚。本研究调查了三周暴露于不同 MP 和食物短缺对贻贝物理防御机制（byssus 生产和特性）的影响. 饥饿显着减少了贝索丝的数量，同时暴露于 MP 和食物短缺抑制了贻贝的粘附能力和条件指数。byssus 线程的长度不受所有实验暴露的影响。编码参与贝索形成的关键蛋白（贻贝足蛋白 mfp-1、-2、-3、-4、-5 和 -6，以及预聚合的胶原蛋白 preCOL-D、-P 和 -NG）的基因转录水平为国会议员和粮食短缺之间的相互作用改变了。这些研究结果表明，食物供应不足会加剧 MP 对贻贝防御的不利影响，这可能对受污染的沿海栖息地中食物有限条件（例如冬季）下贻贝的生存和健康产生影响。