Department of Land, Environment, University of Padova, Agriculture and Forestry-AGRIPOLIS-Viale dell'Università 16, 35020 Legnaro, PD, Italy.
Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, TO, Italy.
Toxins (Basel). 2021 Sep 15;13(9):653. doi: 10.3390/toxins13090653.
and are common pathogens of maize which are known to produce mycotoxins, including moniliformin (MON) and fumonisins (FBs). Fungal secondary metabolism and response to oxidative stress are interlaced, where hydrogen peroxide (HO) plays a pivotal role in the modulation of mycotoxin production. The objective of this study is to examine the effect of HO-induced oxidative stress on fungal growth, as well as MON and FBs production, in different isolates of these fungi. When these isolates were cultured in the presence of 1, 2, 5, and 10 mM HO, the fungal biomass of isolates showed a strong sensitivity to increasing oxidative conditions (27-58% reduction), whereas isolates were not affected or even slightly improved (45% increase). HO treatment at the lower concentration of 1 mM caused an almost total disappearance of MON and a strong reduction of FBs content in the two fungal species and isolates tested. The catalase activity, surveyed due to its crucial role as an HO scavenger, showed no significant changes at 1 mM HO treatment, thus indicating a lack of correlation with MON and FB changes. HO treatment was also able to reduce MON and FB content in certified maize material, and the same behavior was observed in the presence and absence of these fungi, highlighting a direct effect of HO on the stability of these mycotoxins. Taken together, these data provide insights into the role of HO which, when increased under stress conditions, could affect the vegetative response and mycotoxin production (and degradation) of these fungi.
和 是玉米的常见病原体，已知它们会产生霉菌毒素，包括单端孢霉烯族毒素（MON）和伏马菌素（FB）。真菌的次生代谢和对氧化应激的反应是交织在一起的，而过氧化氢（HO）在调节霉菌毒素产生中起着关键作用。本研究的目的是研究 HO 诱导的氧化应激对这些真菌不同分离株的真菌生长以及 MON 和 FBs 产生的影响。当这些分离株在 1、2、5 和 10 mM HO 的存在下培养时， 分离株的真菌生物量对不断增加的氧化条件表现出强烈的敏感性（减少 27-58%），而 分离株则不受影响甚至略有增加（增加 45%）。HO 处理在较低浓度的 1 mM 时，会导致两种真菌和测试的分离株中 MON 的几乎完全消失和 FBs 含量的强烈减少。过氧化氢酶活性（由于其作为 HO 清除剂的关键作用而被调查）在 1 mM HO 处理时没有显示出显著变化，因此表明与 MON 和 FB 变化缺乏相关性。HO 处理还能够降低认证玉米材料中的 MON 和 FB 含量，并且在存在和不存在这些真菌的情况下都观察到了相同的行为，突出了 HO 对这些霉菌毒素稳定性的直接影响。总之，这些数据提供了对 HO 作用的深入了解，当 HO 在应激条件下增加时，可能会影响这些真菌的营养生长和霉菌毒素的产生（和降解）。
