产黄青霉多肽提取物通过调节ABA生物合成和胼胝质沉积来保护本氏烟对TMV的感染

来源：植物生物学

今天，介绍的是云南大学陈穗云王建光团队发表在JXB上的研究论文《Penicillium chrysogenum polypeptide extract protects Nicotiana benthamiana against TMV infection through modulation of ABA biosynthesis and callose priming》。

产黄青霉干菌丝体（PDMP）的多肽提取物可以保护烟草免受烟草花叶病毒（TMV）的侵害，但是PDMP介导的TMV抗性的潜在机制尚不清楚。

在本研究中，作者通过RNA测序分析了这种潜在机制，发现ABA生物合成途径和-13-葡聚糖酶（一种胼胝质降解酶）可能在PDMP诱导的对TMV的抗性反应中起重要作用。

为了验证这一假设，作者成功地产生了一个本氏烟草ABA生物合成突变体，并通过苯胺蓝染色，RT-qPCR，蛋白质印迹和免疫电子显微镜，评估了ABA途径在PDMP诱导的胼胝质的沉积在对TMV抗性反应中的作用。 

结果表明，PDMP通过增加胞质周围的胼胝质沉积来抑制TMV的运动，但是这种现象在ABA生物合成突变体中并未发生。此外，通过用外源ABA处理可以回补PDMP对胼胝质沉积的这些作用。 

作者的结果表明，野生型植物中胞间连丝周围的胼胝质沉积主要是在PDMP诱导的对TMV感染的防御反应期间限制TMV运动的原因，并且ABA的生物合成在PDMP诱导的对TMV防御中起着关键作用。

The polypeptide extract of the dry mycelium of Penicillium chrysogenum (PDMP) can protect tobacco plants from tobacco mosaic virus (TMV), although the potential mechanism underlying PDMP-mediated TMV resistance remains unknown. In our study, we analyzed this potential mechanism via RNA sequencing (RNA-seq) and found that the ABA biosynthetic pathway and β-1,3-glucanase, a callose-degrading enzyme, might play an important role in the PDMP-induced priming of resistance to TMV. To test our hypothesis, we successfully generated a Nicotiana benthamiana ABA biosynthesis mutant and evaluated the role of the ABA pathway in PDMP-induced callose deposition during plasmodesmata resistance to TMV infection via aniline blue staining, quantitative real-time polymerase chain reaction, western blotting, and immunoelectron microscopy. Our results suggested that PDMP can induce callose priming to defend against TMV movement. PDMP inhibited TMV movement by increasing callose deposition around plasmodesmata, but this phenomenon did not occur in the ABA biosynthesis mutant; moreover, these effects of PDMP on callose deposition could be rescued by treatment with exogenous ABA. Our results suggested that callose deposition around plasmodesmata in wild-type plants is mainly responsible for the restriction of TMV movement during the PDMP-induced defensive response to TMV infection and that ABA biosynthesis apparently plays a crucial role in PDMP-induced callose priming for enhancing defense against TMV.