Detailed Description
In order to better understand the present invention, the following examples are further provided to illustrate the content of the present invention, but the content of the present invention is not limited to the following examples.
Example 1 isolation and screening of submerged plant PGPR
(1) Sample collection
Two sediments with high organic matter content (OM ═ 17.35%) and low organic matter content (OM ═ 4.94%) in Hangzhou West lake are selected as two treatments (numbered as H and L), each treatment is carried out in parallel, and the tape grass is planted in a glass jar for 70 days. Collecting the root system of herba Swertiae Dilutae and the deposit around the root system of herba Swertiae Dilutae about 10g, and refrigerating at 4 deg.C. In addition, the locus where the eel grass, the curly pondweed, the watermifoil, the black alga and the microtooth eyeweed in good growth state are located is directly selected from the natural lake of the Hangzhou west lake with low organic matter substrate sludge as the rhizosphere soil collection point (the high organic matter demonstration area has no submerged plant growth), and the number is S. About 10g of plant roots and deposits attached to the periphery of the roots are collected at each site, and the roots and the deposits are refrigerated and stored in a refrigerator at 4 ℃.
(2) Preliminary screening
H, L and 10g of S-group tape grass root system and peripheral attached sediments are respectively weighed in a sterilized conical flask, 90mL of sterile water and sterilized glass beads are added, and shaking culture is carried out at the temperature of 28 ℃ and the speed of 170r/min for 30min to obtain bacterial suspension. Through gradient dilution, 10 is obtained-4、10-5、10-6And (3) respectively sucking 0.1mL of bacterial suspension liquid into a bacterial suspension liquid plate with the concentration, coating the bacterial suspension liquid plate on a root system secretion culture medium for primary screening of growth-promoting bacteria, treating three concentration gradients in each treatment, repeating three gradients in each treatment, and culturing for 5 days in a constant-temperature incubator at 28 ℃. Respectively selecting dominant strains for separation and purification, and storing at-80 ℃ for later use.
The culture medium is root secretion culture medium, a proper amount of tape grass in H, L groups of experimental devices is taken, roots are respectively soaked in ultrapure water, leaves are placed outside and periodically sprayed with water, illumination culture is carried out for 6 hours, root soak solution is freeze-dried to obtain root secretion, and the root secretion solution with the final concentration of 20mg/L is prepared. Sterilizing the root exudate by a 0.22 mu m filter membrane, placing the sterilized exudate into a water bath at 60 ℃ for preheating, sterilizing by 40g/L agar culture medium high-pressure steam, cooling the sterilized exudate into the water bath to 60 ℃, and then mixing the sterilized exudate and the cooled exudate with water according to the volume ratio of 1: 1 mixing to obtain the primary screening culture medium.
(3) Double sieve
And (3) further measuring four growth promotion indexes of P dissolution, indoleacetic acid (IAA) production capability, Cytokinin (CKs) production capability and 1-aminocyclopropane-1-carboxylic Acid (ACC) deaminase activity of the dominant strain obtained by primary screening, and finally screening to obtain three optimal strains (PC2, H19 and L3) which are stored in a refrigerator at the temperature of-80 ℃ for rhizosphere inoculation of submerged plants.
TABLE 1 Table of three PGPR basic information
PGPR is mainly used for promoting the growth and development of crops by synthesizing certain plant hormones, such as auxin analogs, cytokinin, enzyme substances for degrading ethylene and the like. Among the four growth promoting indexes, IAA and CKs can be used as plant hormones to accelerate cell division and growth, so that plant growth is promoted. ACC deaminase can help plants break down the synthetic precursor ACC of ethylene, metabolize it to alpha-ketobutyrate and ammonia, and use it as a carbon and nitrogen source, supplying the bacteria with their growth needs. Phosphorus is one of the essential nutrient elements for plant growth and development, and when the plant body is deficient in phosphorus, the synthesis of important biomolecules such as protein, nucleic acid, coenzyme and the like is affected, so that plant branches are reduced, and the plant is short and small. Phosphorus in combination with Fe in soil3+、Ca2+And Al3+And the like are combined to be water-insoluble and are difficult to be absorbed by plants. The phosphorus-dissolving bacteria can convert insoluble or insoluble phosphorus in plant rhizosphere and natural soil into soluble phosphorus which is easily absorbed and utilized by plants. The PC2 strain has the highest P-dissolving capacity, high IAA and CKs producing capacity and comprehensive capacity greater than H19 and L3, so that the strain has higher application value.
The 16S rRNAs of the three PGPR strains are respectively shown in SEQ ID NO.1-3, and the specific information is shown in Table 1. The PC2 strain has been sent to the China center for type culture Collection (CGMCC) for collection at 6/8/2020, under the classification name: bacillus stratosphericus (Bacillus stratosphericus) PC2, accession number: CCTCC M2020188.
Example 2 Effect of PGPR on Germination of Swertia amara seeds in high organic matter load sediments
Selecting high organic matter sediment (OM ═ 17.35%) and making high-temperature sterilization, then spreading it in culture dish with diameter of 12cm, uniformly placing 100 disinfected and sterilized bitter grass seeds, adding pure water to make them pass through the sediment, every treatment is parallel, at the same time setting no-bacteria as blank control, and making four treatment groups of CK, PC2, H19 and L3, and every culture dish is initially added with bacterial liquor (OD)6001)1mL, adding pure water once after 5 days, supplementing pure water once every 3 days, placing in a 2000lux light incubator for 10 days in total, and illuminating for 12 hours and darkness for 12 hoursAnd measuring the plant height after the experiment is finished.
The experimental result is shown in figure 1, the plant heights of the PC2, H19 and L3 treated groups are increased by 95.7%, 69.6% and 81.2% compared with the blank, the growth promotion effect on the germinated tape grass seeds under the stress of high organic matters is obvious, and the effect of the strain PC2 is optimal.
Example 3 Effect of PGPR on the growth of Sophora alopecuroides seedlings in high organic matter load sediments
Four treatment groups of CK, PC2, H19 and L3 are arranged, and the organic matter content of the selected high organic matter sediment is 17.4%. In each treatment, 15 planting cups (diameter 5cm and height 8cm) are uniformly placed in a box of 35X 50X 30cm, sediment of 5cm height is paved at the bottoms of the planting cups, and five sowthistle seedlings with the same size and biomass are planted in each planting cup. The experiment is carried out under outdoor natural illumination, the experiment time is 7 months to 11 months of 2019 years, the culture temperature range is 5-36 ℃, the experiment period is 120 days, the water is added every 3 days, and the plant rhizosphere is supplemented with a bacterial liquid (OD) by using a disposable dropper every 15 days 6001, 2mL), the blank treatment was replaced with ultrapure water. And (4) respectively collecting samples at 20d, 40d, 60d, 90d and 120d, randomly selecting three planting cups for each treatment in each sampling, collecting plant samples, and measuring the plant height, the root length, the overground fresh weight and the root fresh weight of the plant samples.
The experimental results are shown in fig. 2, and the plant height of the plants is obviously inhibited by blank treatment along with the experimental time. After the experiment is finished, the plant height, the root length, the overground fresh weight and the root fresh weight of the PC 2-treated group are respectively increased by 165.0 percent, 17.4 percent, 378.8 percent and 165.1 percent compared with the blank treatment; the plant height, the root length, the overground fresh weight and the root fresh weight of the H19 treatment group are respectively increased by 143.2 percent, 6.5 percent, 329.8 percent and 92.8 percent compared with the blank treatment; the plant height, the root length, the overground fresh weight and the root fresh weight of the L3 treated group are respectively increased by 89.3 percent, 6.5 percent, 189.0 percent and 72.3 percent compared with the blank treatment, and the comprehensive influence on the growth promotion of the tape grass is PC2> H19> L3.
Sequence listing
<110> institute of aquatic organisms of Chinese academy of sciences
<120> bacillus for promoting recovery of submerged plants in high organic matter bottom mud
<160> 3
<170> SIPOSequenceListing 1.0
<210> 1
<211> 1451
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 1
gtgagtcgcg tgctatacat gcaagtcgag cggacagaag ggagcttgct cccggatgtt 60
agcggcggac gggtgagtaa cacgtgggta acctgcctgt aagactggga taactccggg 120
aaaccggagc taataccgga tagttccttg aaccgcatgg ttcaaggatg aaagacggtt 180
tcggctgtca cttacagatg gacccgcggc gcattagcta gttggtgagg taacggctca 240
ccaaggcgac gatgcgtagc cgacctgaga gggtgatcgg ccacactggg actgagacac 300
ggcccagact cctacgggag gcagcagtag ggaatcttcc gcaatggacg aaagtctgac 360
ggagcaacgc cgcgtgagtg atgaaggttt tcggatcgta aagctctgtt gttagggaag 420
aacaagtgca agagtaactg cttgcacctt gacggtacct aaccagaaag ccacggctaa 480
ctacgtgcca gcagccgcgg taatacgtag gtggcaagcg ttgtccggaa ttattgggcg 540
taaagggctc gcaggcggtt tcttaagtct gatgtgaaag cccccggctc aaccggggag 600
ggtcattgga aactgggaaa cttgagtgca gaagaggaga gtggaattcc acgtgtagcg 660
gtgaaatgcg tagagatgtg gaggaacacc agtggcgaag gcgactctct ggtctgtaac 720
tgacgctgag gagcgaaagc gtggggagcg aacaggatta gataccctgg tagtccacgc 780
cgtaaacgat gagtgctaag tgttaggggg tttccgcccc ttagtgctgc agctaacgca 840
ttaagcactc cgcctgggga gtacggtcgc aagactgaaa ctcaaaggaa ttgacggggg 900
cccgcacaag cggtggagca tgtggtttaa ttcgaagcaa cgcgaagaac cttaccaggt 960
cttgacatcc tctgacaacc ctagagatag ggctttccct tcggggacag agtgacaggt 1020
ggtgcatggt tgtcgtcagc tcgtgtcgtg agatgttggg ttaagtcccg caacgagcgc 1080
aacccttgat cttagttgcc agcattcagt tgggcactct aaggtgactg ccggtgacaa 1140
accggaggaa ggtggggatg acgtcaaatc atcatgcccc ttatgacctg ggctacacac 1200
gtgctacaat ggacagaaca aagggctgcg agaccgcaag gtttagccaa tcccacaaat 1260
ctgttctcag ttcggatcgc agtctgcaac tcgactgcgt gaagctggaa tcgctagtaa 1320
tcgcggatca gcatgccgcg gtgaatacgt tcccgggcct tgtacacacc gcccgtcaca 1380
ccacgagagt ttgcaacacc cgaagtcggt gaggtaacct ttatggagcc agccgccgaa 1440
gtgcagagtg g 1451
<210> 2
<211> 1452
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 2
aggctgcggc gtgctataca tgcaagtcga gcggacagat gggagcttgc tccctgatgt 60
tagcggcgga cgggtgagta acacgtgggt aacctgcctg taagactggg ataactccgg 120
gaaaccgggg ctaataccgg atggttgttt gaaccgcatg gttcaaacat aaaaggtggc 180
ttcggctacc acttacagat ggacccgcgg cgcattagct agttggtgag gtaacggctc 240
accaaggcaa cgatgcgtag ccgacctgag agggtgatcg gccacactgg gactgagaca 300
cggcccagac tcctacggga ggcagcagta gggaatcttc cgcaatggac gaaagtctga 360
cggagcaacg ccgcgtgagt gatgaaggtt ttcggatcgt aaagctctgt tgttagggaa 420
gaacaagtac cgttcgaata gggcggtacc ttgacggtac ctaaccagaa agccacggct 480
aactacgtgc cagcagccgc ggtaatacgt aggtggcaag cgttgtccgg aattattggg 540
cgtaaagggc tcgcaggcgg tttcttaagt ctgatgtgaa agcccccggc tcaaccgggg 600
agggtcattg gaaactgggg aacttgagtg cagaagagga gagtggaatt ccacgtgtag 660
cggtgaaatg cgtagagatg tggaggaaca ccagtggcga aggcgactct ctggtctgta 720
actgacgctg aggagcgaaa gcgtggggag cgaacaggat tagataccct ggtagtccac 780
gccgtaaacg atgagtgcta agtgttaggg ggtttccgcc ccttagtgct gcagctaacg 840
cattaagcac tccgcctggg gagtacggtc gcaagactga aactcaaagg aattgacggg 900
ggcccgcaca agcggtggag catgtggttt aattcgaagc aacgcgaaga accttaccag 960
gtcttgacat cctctgacaa tcctagagat aggacgtccc cttcgggggc agagtgacag 1020
gtggtgcatg gttgtcgtca gctcgtgtcg tgagatgttg ggttaagtcc cgcaacgagc 1080
gcaacccttg atcttagttg ccagcattca gttgggcact ctaaggtgac tgccggtgac 1140
aaaccggagg aaggtgggga tgacgtcaaa tcatcatgcc ccttatgacc tgggctacac 1200
acgtgctaca atggacagaa caaagggcag cgaaaccgcg aggttaagcc aatcccacaa 1260
atctgttctc agttcggatc gcagtctgca actcgactgc gtgaagctgg aatcgctagt 1320
aatcgcggat cagcatgccg cggtgaatac gttcccgggc cttgtacaca ccgcccgtca 1380
caccacgaga gtttgtaaca cccgaagtcg gtgaggtaac cttttaggag ccagccgccg 1440
aagtgacaga tt 1452
<210> 3
<211> 1458
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 3
ggaatggcgg cgtgcctata catgcaagtc gagcgaatgg attaagagct tgctcttatg 60
aagttagcgg cggacgggtg agtaacacgt gggtaacctg cccataagac tgggataact 120
ccgggaaacc ggggctaata ccggataaca ttttgaaccg catggttcga aattgaaagg 180
cggcttcggc tgtcacttat ggatggaccc gcgtcgcatt agctagttgg tgaggtaacg 240
gctcaccaag gcaacgatgc gtagccgacc tgagagggtg atcggccaca ctgggactga 300
gacacggccc agactcctac gggaggcagc agtagggaat cttccgcaat ggacgaaagt 360
ctgacggagc aacgccgcgt gagtgatgaa ggctttcggg tcgtaaaact ctgttgttag 420
ggaagaacaa gtgctagttg aataagctgg caccttgacg gtacctaacc agaaagccac 480
ggctaactac gtgccagcag ccgcggtaat acgtaggtgg caagcgttat ccggaattat 540
tgggcgtaaa gcgcgcgcag gtggtttctt aagtctgatg tgaaagccca cggctcaacc 600
gtggagggtc attggaaact gggagacttg agtgcagaag aggaaagtgg aattccatgt 660
gtagcggtga aatgcgtaga gatatggagg aacaccagtg gcgaaggcga ctttctggtc 720
tgtaactgac actgaggcgc gaaagcgtgg ggagcaaaca ggattagata ccctggtagt 780
ccacgccgta aacgatgagt gctaagtgtt agagggtttc cgccctttag tgctgaagtt 840
aacgcattaa gcactccgcc tggggagtac ggccgcaagg ctgaaactca aaggaattga 900
cgggggcccg cacaagcggt ggagcatgtg gtttaattcg aagcaacgcg aagaacctta 960
ccaggtcttg acatcctctg aaaaccctag agatagggct tctccttcgg gagcagagtg 1020
acaggtggtg catggttgtc gtcagctcgt gtcgtgagat gttgggttaa gtcccgcaac 1080
gagcgcaacc cttgatctta gttgccatca ttaagttggg cactctaagg tgactgccgg 1140
tgacaaaccg gaggaaggtg gggatgacgt caaatcatca tgccccttat gacctgggct 1200
acacacgtgc tacaatggac ggtacaaaga gctgcaagac cgcgaggtgg agctaatctc 1260
ataaaaccgt tctcagttcg gattgtaggc tgcaactcgc ctacatgaag ctggaatcgc 1320
tagtaatcgc ggatcagcat gccgcggtga atacgttccc gggccttgta cacaccgccc 1380
gtcacaccac gagagtttgt aacacccgaa gtcggtgggg taaccttttt ggagcccagc 1440
cgcctaagtg acagagtt 1458