Abd-Alla Mohamed Hemida, Bashandy Shymaa Ryhan, Bagy Magdy Khalil, El-enany Abdel-Wahab Elsadk
Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt,
Ecotoxicology. 2014 Jul;23(5):946-59. doi: 10.1007/s10646-014-1239-1. Epub 2014 Apr 17.
The objective of this study is to explore the response of an activated Rhizobium tibeticum inoculum with a mixture of hesperetin (H) and apigenin (A) to improve the growth, nodulation, and nitrogen fixation of fenugreek (Trigonella foenum graecum L.) grown under nickel (Ni) stress. Three different sets of fenugreek seed treatments were conducted, in order to investigate the activated R. tibeticum pre-incubation effects on nodulation, nitrogen fixation and growth of fenugreek under Ni stress. Group (I): uninoculated seeds with R. tibeticum, group (II): inoculated seeds with uninduced R. tibeticum group (III): inoculated seeds with induced R. tibeticum. The present study revealed that Ni induced deleterious effects on rhizobial growth, nod gene expression, nodulation, phenylalanine ammonia-lyase (PAL) and glutamine synthetase activities, total flavonoids content and nitrogen fixation, while the inoculation with an activated R. tibeticum significantly improved these values compared with plants inoculated with uninduced R. tibeticum. PAL activity of roots plants inoculated with induced R. tibeticum and grown hydroponically at 75 and 100 mg L(-1) Ni and was significantly increased compared with plants receiving uninduced R. tibeticum. The total number and fresh mass of nodules, nitrogenase activity of plants inoculated with induced cells grown in soil treated up to 200 mg kg(-1) Ni were significantly increased compared with plants inoculated with uninduced cells. Plants inoculated with induced R. tibeticum dispalyed a significant increase in the dry mass compared with those treated with uninduced R. tibeticum. Activation of R. tibeticum inoculum with a mixture of hesperetin and apigenin has been proven to be practically important in enhancing nodule formation, nitrogen fixation and growth of fenugreek grown in Ni contaminated soils.
本研究的目的是探索用橙皮素（H）和芹菜素（A）混合物激活的西藏根瘤菌接种物对改善在镍（Ni）胁迫下生长的胡芦巴（Trigonella foenum graecum L.）的生长、结瘤和固氮的反应。进行了三组不同的胡芦巴种子处理，以研究激活的西藏根瘤菌预培养对镍胁迫下胡芦巴结瘤、固氮和生长的影响。第一组（I）：未接种西藏根瘤菌的种子；第二组（II）：接种未诱导的西藏根瘤菌的种子；第三组（III）：接种诱导的西藏根瘤菌的种子。本研究表明，镍对根瘤菌生长、结瘤基因表达、结瘤、苯丙氨酸解氨酶（PAL）和谷氨酰胺合成酶活性、总黄酮含量和固氮产生有害影响；而与接种未诱导的西藏根瘤菌的植物相比，接种激活的西藏根瘤菌显著提高了这些值。接种诱导的西藏根瘤菌并在75和100 mg L(-1)镍浓度下进行水培生长的植物根系的PAL活性，与接种未诱导的西藏根瘤菌的植物相比显著增加。与接种未诱导细胞的植物相比，接种诱导细胞并生长在高达200 mg kg(-1)镍处理土壤中的植物根瘤总数和鲜质量、固氮酶活性显著增加。与用未诱导的西藏根瘤菌处理的植物相比，接种诱导的西藏根瘤菌的植物干质量显著增加。已证明用橙皮素和芹菜素混合物激活西藏根瘤菌接种物对于增强在镍污染土壤中生长的胡芦巴的结瘤、固氮和生长具有实际重要意义。
