The invention discloses a
cysteine protease gene for regulating and controlling
root nodule senescence, and a preparation method and application thereof. According to the preparation method disclosed by the invention, a Japan lotaustralin genomic sequence
library is compared by utilizing the known
cysteine protease gene of
astragalus smicus; after the Japan lotaustralin genomic sequence
library is analyzed and compared on
the internet in a detailed manner, a primer having strong specificity is designed to carry out
gene cloning by taking
initiation codon as the starting point and termination codon as the finishing point; in addition, due to sequencing analysis and comparing analysis, a cloned fragment proves that the
cysteine protease gene for regulating and controlling
root nodule senescence is successfully cloned from the lotaustralin genomic sequence and cDNA (
complementary deoxyribonucleic acid). The invention discloses application of the
cysteine protease gene on leguminous plants; the expression mode of a gene
promoter and the functions of the gene in the
root nodule senescence process are researched by utilizing a histochemical localization technology. Compared with contrast plants, the results show that the root nodule of an RNAi (ribonucleic acid interference)
plant is enlarged; the
nitrogen fixation
enzyme activity is increased; senescence of the root nodule is delayed; the effective
nitrogen fixation time of the root nodule is prolonged; growth of the
plant is more vigorous; the
cysteine protease gene disclosed by the invention has application prospect on leguminous crops.