ABSTRACT Nowadays, calcium (Ca2+) and methylglyoxal (MG) are all deemed to be second messengers in plants, which participate in various physiological processes, such as seed germination, seedling establishment, plant growth and development, as well as response to environmental stress. However, the Ca2+-MG interaction in the development of thermotolerance in maize seedlings remains unclear. Here, using maize seedlings as materials, the crosstalk between Ca2+ and MG signaling in the acquisition of thermotolerance was explored. The results showed that root-irrigation with Ca2+ and MG alone or in combination increased the survival rate of maize seedlings under heat stress, mitigated the decrease in the tissue vitality, and reduced the membrane lipid peroxidation (in term of the content of malondialdehyde), indicating that Ca2+ and MG could improve the thermotolerance in maize seedlings. In addition, MG-improved thermotolerance was impaired by ethylene glycol-bis(b-aminoethylether)-N,N,N΄,N΄-tetraacetic acid (a Ca2+ chelator), La3+ (plasma membrane Ca2+ channel blocker), ruthenium red (a mitochondrial Ca2+ channel blocker), neomycin (vacuole Ca2+ channel blocker), caffeine (an endoplasmic reticulum Ca2+ channel blocker), and calmodulin antagonists (chlorpromazine and trifluoperazine), respectively. Also, MG scavengers (N-acetyl-cysteine, aminoguanidine, and vitamin B6) had no significant effect on Ca2+-triggered thermotolerance (in terms of survival rate, malondialdehyde, and tissue vitality) of maize seedlings. The data illustrated that calcium signaling regulated MG-improved thermotolerance in maize seedlings by mobilizing intracellular and extracellular Ca2+ pools.

中文翻译：

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钙信号对甲基乙二醛改善玉米（Zea mays L）幼苗耐热性的调节作用

摘要 目前，钙（Ca2+）和甲基乙二醛（MG）均被认为是植物体内的第二信使，参与各种生理过程，如种子萌发、幼苗建立、植物生长发育以及对环境胁迫的响应。然而，Ca2+-MG 在玉米幼苗耐热性发展中的相互作用仍不清楚。在这里，以玉米幼苗为材料，探讨了获得耐热性时 Ca2+ 和 MG 信号之间的串扰。结果表明，Ca2+和MG单独或联合灌根提高了玉米幼苗在热胁迫下的成活率，减轻了组织活力的下降，减少了膜脂过氧化（丙二醛含量），表明Ca2+和MG可以提高玉米幼苗的耐热性。此外，乙二醇-双（b-氨基乙醚）-N,N,N΄,N΄-四乙酸（一种 Ca2+ 螯合剂）、La3+（质膜 Ca2+ 通道阻滞剂）、钌红（线粒体 Ca2+ 通道阻滞剂）、新霉素（液泡 Ca2+ 通道阻滞剂）、咖啡因（内质网 Ca2+ 通道阻滞剂）和钙调素拮抗剂（氯丙嗪和三氟拉嗪）​​。此外，MG 清除剂（N-乙酰半胱氨酸、氨基胍和维生素 B6）对 Ca2+ 触发的玉米幼苗的耐热性（在存活率、丙二醛和组织活力方面）没有显着影响。