Microcystin-LR induces mitotic spindle assembly disorders in Vicia faba by protein phosphatase inhibition and not reactive oxygen species induction

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• 作者：Tamá ; s Garda^a ; ³ ; ^{gtamas0516@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Zoltá ; n Kó ; nya^a ; ¹ ; ³ ; ^{konya.zoltan@med.unideb.hu" class="auth_mail" title="E-mail the corresponding author} ; Ildikó ; Tá ; ndor^a ; ^{dike15ster@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Dá ; niel Beyer^a ; ² ; ^{beyerdani@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Gá ; bor Vasas^a ; ^{vasas.gabor@science.unideb.hu" class="auth_mail" title="E-mail the corresponding author} ; Ferenc Erdődi^b ; ^{erdodi@med.unideb.hu" class="auth_mail" title="E-mail the corresponding author} ; Gyö ; rgy Vereb^c ; ^{vereb@med.unideb.hu" class="auth_mail" title="E-mail the corresponding author} ; Georgina Papp^a ; ^{papp.georgina93@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Milá ; n Riba^a ; ^{ribamilan@freemail.hu" class="auth_mail" title="E-mail the corresponding author} ; Má ; rta M-Hamvas^a ; ^{hamvas.marta@science.unideb.hu" class="auth_mail" title="E-mail the corresponding author} ; Csaba Má ; thé ; ^a ; ^{mathe.csaba@science.unideb.hu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Microcystin-LR ; Spindle alteration ; Protein phosphatase ; Reactive oxygen species ; Vicia faba
• 刊名：Journal of Plant Physiology
• 出版年：2016
• 出版时间：20 July 2016
• 年：2016
• 卷：199
• 期：Complete
• 页码：1-11
• 全文大小：2040 K

文摘

We aimed to reveal the mechanisms of mitotic spindle anomalies induced by microcystin-LR (MCY-LR), a cyanobacterial toxin in Vicia faba, a well-known model in plant cell and molecular biology. MCY-LR inhibits type 1 and 2A phosphoserine/threonine specific protein phosphatases (PP1 and PP2A) and induces reactive oxygen species (ROS) formation. The cytoskeleton is one of the main targets of the cyanotoxin during cytopathogenesis. Histochemical-immunohistochemical and biochemical methods were used. A significant number of MCY-LR induced spindle alterations are described for the first time. Disrupted, multipolar spindles and missing kinetochore fibers were detected both in metaphase and anaphase cells. Additional polar microtubule (MT) bundles, hyperbundling of spindle MTs, monopolar spindles, C-S- shaped, additional and asymmetric spindles were detected in metaphase, while midplane kinetochore fibers were detected in anaphase cells only. Several spindle anomalies induced mitotic disorders, i.e. they occurred concomitantly with altered sister chromatid separation. Alterations were dependent on the MCY-LR dose and exposure time. Under long-term (2 and mainly 6 days’) exposure they were detected in the concentration range of 0.1–20 μg mL⁻¹ MCY-LR that inhibited PP1 and PP2A significantly without significant ROS induction. Elevated peroxidase/catalase activities indicated that MCY-LR treated V. faba plants showed efficient defense against oxidative stress. Thus, although the elevation of ROS is known to induce cytoskeletal aberrations in general, this study shows that long-term protein phosphatase inhibition is the primary cause of MCY-LR induced spindle disorders.