Seedling period is an important stage of plant growth. This research was mainly to analysis the influence of chitosan on wheat seedling growth and physiological mechanisms under drought stress. The results showed that the group coated with chitosan significantly improved the growth index such as germination rate, wet weight, root length, root active, and impacted physiological indices such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT)), the content of malwondialdehyde (MDA) and chlorophyll compared with CK under drought stress. Activities of POD, CAT and SOD increased and then decreased, the content of MDA increased under drought stress. But. variation rates of the group coated with chitosan were slower than that of CK, which indicates that chitosan can significantly improve anti-oxidant enzymes activity to clear timely active oxygen and reduce the content of MDA so as to alleviate the degree of damage in the drought stress and make seedlings grow better. The results also showed that chitosan improved chloro-phyll content than that of CK, which demonstrated that chlorophyll content significantly influenced the photosynthetic efficiency of the mutant and added wheat above ground biomass and the field experiment results showed that chitosan increased yield 13.6% than that of CK

Soybean seeds suffer attacks of various pests that result in a decreased yield in northeastern China. Until recently, people use pesticides such as insecticides to achieve the goal of controlling pests. Chitosan extracted from deacetylation of chitin is promising candidates as a seed-coating agent to control agrotis ypsilon, soybean pod borer, and soybean aphid effectively. An experimental study on influences of chitosan with different concentrations on pest controlling and soybean growth was made in the paper. Coating based on chitosan was used as a feeding deterrent and for enhancing the germination and quality of soybean seeds. Results indicated that all chitosan coating had a significant effect on antifeeding against pests; with the increasing concentration, antifeedant rate (AR) were increased obviously, especially when in the concentration of 5%, santifeedant rate of agrotis ypsilon, soybean pod borer, and soybean aphid reached 82.89%, 87.24%, and 80.21%, respectively. Also chitosan coating increased seed germination, plant growth, and soybean yield efficiently, especially when, in the concentration of 5%, the yield was increased by about 20% compared with CK. The application of chitosan in soybean seed coated is an appropriate option to control pests replacing high-toxicity pesticides and enhance soybean yield.

Plant flavonoids have attracted increasing attention as new antimicrobial agents or adjuvants. In our previous work, it was confirmed that the cell membrane is the major site of plant flavonoids acting on the Gram-positive bacteria, which likely involves the inhibition of the respiratory chain. Inspired by the similar structural and antioxidant characters of plant flavonoids to hydro-menaquinone (MKH2), we deduced that the quinone pool is probably a key target of plant flavonoids inhibiting Gram-positive bacteria. To verify this, twelve plant flavonoids with six structural subtypes were preliminarily selected, and their minimum inhibitory concentrations (MICs) against Gram-positive bacteria were predicted from the antimicrobial quantitative relationship of plant flavonoids to Gram-positive bacteria. The results showed they have different antimicrobial activities. After their MICs against Staphylococcus aureus were determined using the broth microdilution method, nine compounds with MICs ranging from 2 to 4096 μg/mL or more than 1024 μg/mL were eventually selected, and then their MICs against S. aureus were determined interfered with different concentrations of menaquinone−4 (MK−4) and the MKs extracted from S. aureus. The results showed that the greater the antibacterial activities of plant flavonoids were, the more greatly their antibacterial activities decreased along with the increase in the interfering concentrations of MK−4 (from 2 to 256 μg/mL) and the MK extract (from 4 to 512 μg/mL), while those with the MICs equal to or more than 512 μg/mL decreased a little or remained unchanged. In particular, under the interference of MK−4 (256 μg/mL) and the MK extract (512 μg/mL), the MICs of α-mangostin, a compound with the greatest inhibitory activity to S. aureus out of these twelve plant flavonoids, increased by 16 times and 8 to 16 times, respectively. Based on the above, it was proposed that the quinone pool is a key target of plant flavonoids inhibiting Gram-positive bacteria, and which likely involves multiple mechanisms including some enzyme and non-enzyme inhibitions.

A novel Streptomyces strain, designated TRM 75549T, was separated from a sample of sand in Pimo, Taklimakan desert, Xinjiang, North-West China. Phylogenetic analyses of the 16S rRNA gene sequences placed strain TRM75549T within the genus Streptomyces with the highest similarities to Streptomyces flavoviridis NBRC 12772T (98.76%). The whole-genome average nucleotide identity (ANI) value between strain TRM75549T and S. flavoviridis NBRC 12772T is 88.20%. Digital DNA-DNA hybridization (dDDH) value between strain TRM75549T and S. flavoviridis NBRC 12772T is 44.10%. They are well below the recommended 95-96% and 70% cut-off points for designated species respectively. A multi-locus sequence analysis of five house-keeping genes (atpD, gyrB, recA, rpoB and trpB) and phylogenomic analysis also illustrated that strain TRM75549T should be assigned to the genus Streptomyces. Strain TRM75549T contained MK-9 (H6) and MK-9 (H8) as predominant menaquinones. The diagnostic diamino acid of cell walls was identified as LL-diaminopimelic acid and Meso-diaminopimelic. The whole-cell sugar pattern of strain TRM 75549T consisted of mannose and glucose. The major fatty acids (>5%) were iso-C14:0, iso-C15:0, anteiso-C15:0, iso-C16:1H, iso-C16:0. The polar lipids were diphosphatidylglycerol, lysophosphatidylglycerol, phosphatidylethanolamine, phospholipids, phosphatidylglycerol, phosphatidylinositol, phosphatiylinositol mannosides and unidentified phospholipids. Strain TRM75549T could be differentiated from S. flavoviridis NBRC 12772T, based on physiological and biochemical characteristics. Based on the data from this polyphasic study presented above, strain TRM75549T is represent ative of a novel species of the genus Streptomyces, for which the name Streptomyces pimoensis sp. nov. is proposed. The type strain is TRM75549T (=CCTCC AA 2020054T=LMG 32221T ).

Due to the severity of the disease and yield losses of corn, this study had achieved a novel corn seed coating agent which was prepared with polysaccharide, fertilizer, microelement and other assistants as raw materials. The dilution and the pH value of the corn seed coating agent, were studied. And the biological toxicity and potential hazards of the agent to environmental protection were assessed. Over the whole trial, the best formula and optimum conditions of a new corn seed coating agent were determined. Also results indicated that compared with the traditional one Jinong No. 4, yields of corn was increased over 9.5%, but cost was reduced over 18.75%. To sum up, this agent self-made had three primary characteristics of high yield, less cost and friendly environment. So it had an important value of application and promotion in main production zone of corn and can bring us obvious economic and environmental benefits