Guo B Z, Cleveland T E, Brown R L, Widstrom N W, Lynch R E, Russin J S
Insect Biology and Population Management Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Tifton, Georgia 31793, USA.
J Food Prot. 1999 Mar;62(3):295-9. doi: 10.4315/0362-028x-62.3.295.
This study examined the distribution of two antifungal proteins, ribosome-inactivating protein (RIP) and zeamatin, in maize kernel tissues. Proteins were extracted from endosperm (including aleurone layer) and embryo tissues of imbibed maize kernels. Western blot analyses revealed that RIP-like protein was present at higher levels in endosperm than in embryo tissues, whereas zeamatin-like protein was more concentrated in embryo tissues than in endosperm tissues. However, there were three protein bands in the endosperm and two bands in the embryo that reacted to anti-RIP antibody in Western blot analyses. Tissue prints were conducted to localize the antifungal proteins. Imbibed kernels were cut longitudinally and transversely and blotted onto nitrocellulose membranes. Using antibodies against maize RIP and zeamatin, RIP was found primarily in the aleurone layer of the endosperm and glandular layer of scutellum, whereas zeamatin was located mainly in the kernel embryo. These results provide insight into the potential functions of these antifungal proteins, especially since the presence of RIP and zeamatin within maize kernels uniquely protects kernels from pathogens.
本研究检测了两种抗真菌蛋白，即核糖体失活蛋白（RIP）和玉米素，在玉米籽粒组织中的分布情况。从吸胀的玉米籽粒的胚乳（包括糊粉层）和胚组织中提取蛋白质。蛋白质免疫印迹分析显示，胚乳中类RIP蛋白的含量高于胚组织，而类玉米素蛋白在胚组织中的浓度高于胚乳组织。然而，在蛋白质免疫印迹分析中，胚乳中有三条蛋白带，胚中有两条蛋白带与抗RIP抗体发生反应。进行组织印记以定位抗真菌蛋白。将吸胀的籽粒纵向和横向切开，然后印迹到硝酸纤维素膜上。使用针对玉米RIP和玉米素的抗体，发现RIP主要存在于胚乳的糊粉层和盾片的腺层中，而玉米素主要位于籽粒胚中。这些结果为这些抗真菌蛋白的潜在功能提供了见解，特别是因为玉米籽粒中RIP和玉米素的存在能独特地保护籽粒免受病原体侵害。
