Plant Pathology Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.
Agricultural Chemistry Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.
Pestic Biochem Physiol. 2021 Jan;171:104721. doi: 10.1016/j.pestbp.2020.104721. Epub 2020 Oct 16.
Green mold, caused by Penicillium digitatum, is the most economically important postharvest disease of orange fruit worldwide. The aim of this study was to evaluate the effect of β-aminobutyric acid (BABA) treatment on the inhibition of P. digitatum both in orange fruit and in vitro as well as the possible mechanisms of action. BABA at 125 mM significantly inhibited mycelial growth, spore germination, and germ tube elongation of P. digitatum by 93.3, 90.3, and 90.5%, respectively. The relative electrical conductivity of mycelium was increased for a period of 0-36 h after treated with BABA at 125 mM. Furthermore, BABA caused a high level of malondialdehyde (MDA) in P. digitatum mycelia during four days of incubation. The ergosterol content in the plasma membrane of P. digitatum was significantly lower in BABA-treated mycelia. Also, protein and sugar leakage were increased with BABA treatment compared with that in the control. Besides, BABA caused a considerable reduction in the total lipid content of P. digitatum mycelia at 125 mM. Scanning electron microscopy (SEM) of P. digitatum treated with BABA at 125 mM showed shrunken, distorted, and collapsed mycelia. The application of BABA at 125 mM in orange fruit inoculated with P. digitatum suppressed disease incidence and disease severity by 74.6 and 77.3%, respectively, compared to untreated fruit. Moreover, the activity of defense-related enzymes, including peroxidase (POD), polyphenoloxidase (PPO), and phenylalanine ammonia-lyase (PAL) were significantly enhanced in the orange fruit treated with BABA at 125 mM.
绿霉病由指状青霉引起，是全球柑橘果实最重要的采后病害。本研究旨在评估β-氨基丁酸（BABA）处理对抑制柑橘果实中青霉生长以及离体条件下青霉生长的效果，同时还探讨了其可能的作用机制。125mM 的 BABA 可分别显著抑制青霉的菌丝生长、孢子萌发和芽管伸长，抑制率分别为 93.3%、90.3%和 90.5%。用 125mM 的 BABA 处理后，在 0-36h 期间，菌丝的相对电导率增加。此外，BABA 在 4 天的孵育期内导致青霉菌丝中丙二醛（MDA）含量升高。BABA 处理的青霉菌丝质膜中的麦角固醇含量显著降低。此外，与对照相比，BABA 处理导致青霉菌丝的蛋白质和糖渗漏增加。同时，BABA 在 125mM 时使青霉菌丝的总脂质含量显著降低。用 125mM 的 BABA 处理的青霉的扫描电子显微镜（SEM）显示菌丝皱缩、变形和崩溃。与未处理的果实相比，在接种青霉的柑橘果实中应用 125mM 的 BABA 可分别抑制 74.6%和 77.3%的发病率和病情严重度。此外，在 125mM 的 BABA 处理的柑橘果实中，与防御相关的酶的活性，包括过氧化物酶（POD）、多酚氧化酶（PPO）和苯丙氨酸解氨酶（PAL），显著增强。
