Melanin-Independent Accumulation of Turgor Pressure in Appressoria of Phakopsora pachyrhizi
Melanin-Independent Accumulation of Turgor Pressure in Appressoria of Phakopsora pachyrhizi
复制标题
DOI：
10.1094/phyto-12-13-0335-r
复制
发表时间：
2014-09-01
期刊：
影响因子：
3.2
通讯作者：
Hartman, Glen L.
中科院分区：
文献类型：
--
作者：
Chang, Hao-Xun;Miller, Lou Ann;Hartman, Glen L.
一些植物病原真菌的附着体积累膨胀压力，产生机械力，使菌丝直接穿透表皮。黑色素作为渗透压的不渗透屏障，使附着体积累较高的膨压。附着症中黑色素的缺乏降低了肿胀压力，损害了感染过程。在大豆锈菌Phakopsora pachyRhi中，附着体是透明的。我们的目标是确保附着体细胞壁和质膜之间不存在特定的黑色素层，并确定附着体的膨压。我们证明，两种黑色素生物合成抑制剂既不能降低肿胀压力，也不能抑制感染过程。透射电子显微镜还显示附着体细胞壁和质膜之间没有黑色素层。此外，根据模拟不同渗透压的胞外渗透压的不同，拟青霉附着体的膨压为5~6兆帕。这是第一个表明附着性青霉的膨压积累不受黑色素影响的报道。
Appressoria of some plant-pathogenic fungi accumulate turgor pressure that produces a mechanical force enabling the direct penetration of hyphae through the epidermis. Melanin functions as an impermeable barrier to osmolytes, which allows appressoria to accumulate high turgor pressure. Deficiency of melanin in appressoria reduces turgor pressure and compromises the infection process. In Phakopsora pachyrhizi, the soybean rust pathogen, the appressoria are hyaline. Our objective was to ensure the absence of a melanin layer specifically between the appressorial cell wall and plasma membrane, as well as to determine the turgor pressure of P. pachyrhizi appressoria. We demonstrated that two melanin biosynthesis inhibitors neither reduced turgor pressure nor compromised the infection process. Transmission electron microscopy also showed the absence of a melanin layer between the appressorial cell wall and plasma membrane. In addition, the turgor pressure of P. pachyrhizi appressoria was 5 to 6 MPa, based on extracellular osmolytes used to simulate different osmotic pressures. This is the first report showing that turgor pressure accumulation of P. pachyrhizi appressoria was independent of melanin.