A method for preparing soybean root exudates that efficiently promotes soybean rhizobia to compete for nodulation

Abstract

The invention discloses a preparation method of a soybean root exudate for efficiently promoting competitive nodulation of rhizobium japonicum, and belongs to the technical field of bioengineering. The method comprises the following steps: (1) sterilizing the surface of a soybean seed; (2) moving the sterilized soybean seed into a YMA agar watch glass under the aseptic condition to germinate, moving to a nitrogen-free Rigaud-Puppo nutrient solution of which the concentration is 30%, to culture after the seed is germinated, and collecting the soybean root exudate on the 12 day of culturing, so as to obtain the soybean root exudate for efficiently promoting competitive nodulation of the rhizobium japonicum. The preparation method has the advantages: the best concentration of the nitrogen-free Rigaud-Puppo nutrient solution is confirmed to be 30%, the soybean root exudate collected on the 12 day of culturing remarkably improves the expression of a nodulation gene of the rhizobium japonicum, and the effect of efficiently promoting competitive nodulation of the soybean is further reflected.

Description

technical field [0001] The invention belongs to the technical field of bioengineering, and in particular relates to a preparation method of soybean root exudates that can efficiently promote the competitive nodulation of soybean rhizobia. Background technique [0002] The symbiotic system composed of rhizobia and leguminous plants is the system with the highest biological nitrogen fixation efficiency in nature, and its nitrogen fixation accounts for 3 / 4 of the total biological nitrogen fixation, becoming the main nitrogen source for agricultural production. The symbiotic system of soybean and soybean rhizobia is a biological A typical representative of nitrogen fixation. The use of soybean rhizobia to inoculate legumes to improve their nitrogen fixation efficiency has a history of more than 100 years and has been widely used in many countries as a cost-effective agricultural measure. However, in China, the origin of soybean, the inoculation area of ​​soybean rhizobia only a...

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Problems solved by technology

[0004] The expression of soybean rhizobia nod gene is affected by the host soybean root exudates, and many studies mostly use pure flavonoid substances, daidzein or soybean seedling root extracts to replace soybean root exudates, but in fact, legume root The components of exudates are complex. Up to now, more than 4,000 types of flavonoids in the root exudates of leguminous plants have been found. Although some single pure components or a combination of several pure components can affect the nod gene of soybean rhizobium expression, but the research results are somewhat one-sided; daidzein and soybean seedling root extracts can affect rhizobium competition for nodulation, but in the preparation process, soybean root tissue is also included, which cannot really simulate soybean root extracts. Actual environment; In addition, the collection of soybean root exudates that have been reported so far is mostly focused on the design of the collection device, and there is greater subjectivity in the cultivation conditions and collection time. The components and concentrations are unknown, and the effectiveness It is also impossible to evaluate, which restricts the in-depth research to a certain extent.

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