Antagonistic endophytic bacteria associated with nodules of soybean (Glycine max L. ) and plant growth-promoting properties

Abstract A total of 276 endophytic bacteria were isolated from the root nodules of soybean (Glycine max L.) grown in 14 sites in Henan Province, China. The inhibitory activity of these bacteria against pathogenic fungus Phytophthora sojae 01 was screened in vitro. Six strains with more than 63% inhibitory activities were further characterized through optical epifluorescence microscopic observation, sequencing, and phylogenetic analysis of 16S rRNA gene, potential plant growth-promoting properties analysis, and plant inoculation assay. On the basis of the phylogeny of 16S rRNA genes, the six endophytic antagonists were identified as belonging to five genera: Enterobacter, Acinetobacter, Pseudomonas, Ochrobactrum, and Bacillus. The strain Acinetobacter calcoaceticus DD161 had the strongest inhibitory activity (71.14%) against the P. sojae 01, which caused morphological abnormal changes of fungal mycelia; such changes include fracture, lysis, formation of a protoplast ball at the end of hyphae, and split ends. Except for Ochrobactrum haematophilum DD234, other antagonistic strains showed the capacity to produce siderophore, indole acetic acid, and nitrogen fixation activity. Regression analysis suggested a significant positive correlation between siderophore production and inhibition ratio against P. sojae 01. This study demonstrated that nodule endophytic bacteria are important resources for searching for inhibitors specific to the fungi and for promoting effects for soybean seedlings.

Screening and characterization of endophytic Bacillus and Paenibacillus strains from medicinal plant Lonicera japonica for use as potential plant growth promoters

Abstract A total of 48 endophytic bacteria were isolated from surface-sterilized tissues of the medicinal plant Lonicera japonica, which is grown in eastern China; six strains were selected for further study based on their potential ability to promote plant growth in vitro (siderophore and indoleacetic acid production). The bacteria were characterized by phylogenetically analyzing their 16S rRNA gene similarity, by examining their effect on the mycelial development of pathogenic fungi, by testing their potential plant growth-promoting characteristics, and by measuring wheat growth parameters after inoculation. Results showed that the number of endophytic bacteria in L. japonica varied among different tissues, but it remained relatively stable in the same tissues from four different plantation locations. Among the three endophytic strains, strains 122 and 124 both had high siderophore production, with the latter showing the highest phosphate solubilization activity (45.6 mg/L) and aminocyclopropane-1-carboxylic acid deaminase activity (47.3 nmol/mg/h). Strain 170 had the highest indoleacetic acid (IAA) production (49.2 mg/L) and cellulase and pectinase activities. After inoculation, most of the six selected isolates showed a strong capacity to promote wheat growth. Compared with the controls, the increase in the shoot length, root length, fresh weight, dry weight, and chlorophyll content was most remarkable in wheat seedlings inoculated with strain 130. The positive correlation between enzyme (cellulose and pectinase) activity and inhibition rate on Fusarium oxysporum, the IAA production, and the root length of wheat seedlings inoculated with each tested endophytic strain was significant in regression analysis. Deformity of pathogenic fungal mycelia was observed under a microscope after the interaction with the endophytic isolates. Such deformity may be directly related to the production of hydrolytic bacterial enzymes (cellulose and pectinase). The six endophytic bacterial strains were identified to be Paenibacillus and Bacillus strains based on the results of 16S rRNA gene sequencing analysis and their physiological and biochemical characteristics. Results indicate the promising application of endophytic bacteria to the biological control of pathogenic fungi and the improvement of wheat crop growth.

Clinical application of free perforator hypothenar flap for thumb pulp defect / 中华整形外科杂志

<p><b>OBJECTIVE</b>To summarize the therapeutic effect of free perforator hypothenar flap for thumb pulp defect.</p><p><b>METHODS</b>From Jun. 2012 to Mar. 2013,8 cases with thumb pulp defect accompanied with exposure of phalanges ans tendons were treated by free ipsilateral perforator hypothenar flap. The flaps were 1.4 cm x 2.0 cm-1.8 cm x 2.2 cm in size. Ulnar finger artery in the flap was anastomosed with thumb artery. The accompanied veins and superficial veins were respectively anastomosed with thumb dorsal veins. Nerve branches in flaps were sutured with unilateral finger nerve to reconstruct flap feeling with 9-0 thread. Wounds in the hypothenar donor site were sutured directly.</p><p><b>RESULTS</b>All the flaps survived completely with primary healing both in donor and recipient area. 8 cases (8 fingers) were followed up for 6-13 months (average 9 months). The flaps appearance, texture were good. The two-point discrimination distance on flap was 7-10 mm. The active and passive movement of thumb joints was normal. There was no complain about the feeling at the donor site. Linear scar was left on the donor site. Patients hand grip strength was not decreased.</p><p><b>CONCLUSIONS</b>The free perforator hypothenar flap which has constant vascular anatomy is a new method for thumb soft tissue defect with less morbidity to donor site. The operative procedures are relatively simple.</p>

Reconstruction of small skin defect on children heel with V-Y advanced flap pedicled with perforator of peroneal artery at posterior lateral malleolus / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic effect of V-Y advanced flap pedicled with perforator of peroneal artery at posterior lateral malleolus for small skin defect on children heel.</p><p><b>METHODS</b>From Mar. 2012 to Jan. 2014, 9 children with small skin defects on heel were treated with adjacent V-Y advanced flap pedicled with perforator of peroneal artery at posterior lateral malleolus. The flaps were 8.0 cm x 4.0 cm to 9.0 cm x 4.5 cm in size and the wounds at donor sits were directly closed.</p><p><b>RESULTS</b>All flaps survived completely with primary healing. 9 cases were followed up for 6-12 months( average, 9 months). The flaps had good match with surrounding tissue in texture and color. The function of ankle was normal. All the parents were satisfied with functional and cosmetic results.</p><p><b>CONCLUSIONS</b>It is a safe and practical method for treatment of small skin defect on children heel with adjacent V-Y advanced flap pedicled with perforator of peroneal artery at posterior lateral malleolus.</p>

Reconstruction of soft tissue defects at finger tip with relay flaps pedicled by perforator from digital artery / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the application of relay flaps pedicled by perforator from digital artery for reconstruction of soft tissue defects at finger tip.</p><p><b>METHODS</b>From Mar. 2012 to Jun. 2014, 9 cases with soft tissue defects at finger tip were reconstructed with relay flaps at one side of finger pedicled by perforator from digital artery. The flap size ranged from 1.3 cm x 1.6 cm to 1.6 cm x 2.2 cm. The defects at donor sites were covered by adjacent web perforator V-Y advanced flaps.</p><p><b>RESULTS</b>All the 18 flaps in 9 cases survived completely with primary healing both in recipient and donor sites. The patients were followed up for 5 months to 2 years ( average, 12 months) with good elasticity and cosmetic results. No pain happened in the treated finger. The 2-point discrimination distance was 7-8 mm in fingertip flaps, and 10-12 mm in web perforator flaps. Hand function was graded as excellent in 7 cases, good in 2 cases, based on ATM assessment. The affected fingers had normal temperature and cold-resistance during winter. The width and depth of web in the donor site were not affected.</p><p><b>CONCLUSIONS</b>The relay flaps pedicled by perforator from digital artery can be applied for reconstruction of soft tissue defects at finger tip. The procedure is easy with satisfactory results and reservation of main artery. No skin graft is necessary for closure of defects on donor sites.</p>

Identification and characterization of the endophytic plant growth prompter Bacillus Cereus strain mq23 isolated from Sophora Alopecuroides root nodules

Endophytes MQ23 and MQ23R isolated from Sophora alopecuroides root nodules were characterized by observing their ability to promote plant growth and employing molecular analysis techniques. Results showed that MQ23 and MQ23R are potential N2-fixing endophytes and belong to the same species as Bacillus cereus. MQ23 was shown to be able to produce siderophores, IAA, and demonstrate certain antifungal activity to plant pathogenic fungi. Co-inoculation with MQ23+MQ23II showed a more significant effect than inoculation alone in vitro for most of positive actions suggesting they have a cooperative interaction. Results of plant inoculation with endophytes indicated that the growth indexes of co-inoculated MQ23+MQ23II were higher than those of inoculated alone (p<0.05) (the exception being for root fresh weight) when compared to negative control. There have been little of any studies of nonrhizobial putative endophytes with growth-promotion attributes in S. alopecuroides root nodules. This could be exploited as potential bio-inoculants and biocontrol agents in agriculture.