McWRI1, a transcription factor of the AP2/SHEN family, regulates the biosynthesis of the cuticular waxes on the apple fruit surface under low temperature.

Cuticular waxes of plant and organ surfaces play an important role in protecting plants from biotic and abiotic stress and extending the freshness, storage time and shelf life in the post-harvest agricultural products. WRI1, a transcription factor of AP2/SHEN families, had been found to trigger the related genes taking part in the biosynthesis of seed oil in many plants. But whether WRI1 is involved in the biosynthesis of the cuticular waxes on the Malus fruits surface has been unclear. We investigated the changes of wax composition and structure, the related genes and WRI1 expression on Malus asiatica Nakai and sieversii fruits with the low temperature treatments, found that low temperature induced the up-regulated expression of McWRI1, which promoted gene expression of McKCS, McLACs and McWAX in very-long-chain fatty acid biosynthesis pathway, resulting in the accumulation of alkanes component and alteration of wax structure on the fruit surface. Corresponding results were verified in McWRI1 silenced by VIGS, and WRI1 silenced down-regulated the related genes on two kinds of fruits, it caused the diversity alteration in content of some alkanes, fatty acid and ester component in two kinds of fruits. We further conducted Y1H assay to find that McWRI1 transcription factor activated the promoter of McKCS, McLAC and McWAX to regulate their expression. These results demonstrated that McWRI1 is involved in regulating the genes related synthesis of very long chain fatty acid on surface of apple fruits in storage process, providing a highlight for improvement of the modified atmosphere storage of apple fruits.

An Apple Fruit Fermentation (AFF) Treatment Improves the Composition of the Rhizosphere Microbial Community and Growth of Strawberry (Fragaria × ananassa Duch 'Benihoppe') Seedlings.

Plant growth can be promoted by the application of apple fruit fermentation (AFF), despite unclear of the underlying mechanisms, the effects involved in AFF on rhizosphere microorganisms have been hypothesized. We investigated the consequences of applying AFF alone or in combination with Bacillus licheniformis to strawberry tissue culture seedlings in vitro, the analyses of Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rDNA were performed to determine AFF effects on rhizosphere. Moreover, the growth index and antioxidant enzyme activities were determined 30 days after treatments. We identified five dominant bacteria in AFF: Coprinus atramentarius, Bacillus megaterium, Bacillus licheniformis, Weissella and B. subtilis. The greatest number of bacterial species were observed in the rhizosphere of control matrix (water treated), and the lowest diversity appeared in the rhizosphere soil treated with 108 cfu/mL B. licheniformis alone. Combining AFF plus B. licheniformis in one treatment resulted in the largest leaf area, plant height, root length, plant weight, and the markedly higher activities of antioxidant enzymes. We conclude that a combination of AFF plus B. licheniformis treatment to matrix can increase antioxidant enzymes activities in strawberry seedlings, optimize the status of rhizosphere microbial, and promote plant growth.

[Community structure and its dynamics of predatory arthropod in jujube orchards intercropped with different herbage species].

By using community structural characteristic indices and principal component analysis, this paper studied the community structure and its dynamics of predatory arthropod in the jujube orchards intercropped with Astrugalus complanatus, Trifolium repen, Lotus comiculotus, and Medicago sativa. The results showed that in all test jujube orchards, spider and predatory insects were the predominant components of the predatory arthropod community, and their relative abundances were 48.3% - 52.7% and 38.8% - 44.4% , respectively. There were significant differences (P < 0.05) in the mean density, diversity, and evenness of the most common predatory arthropod groups in the jujube orchards intercropped with different herbage species, with the sequence of intercropped with Lotus comiculotus > Medicago sativa > Astrugalus complanatu > Trifolium repens, but for dominant concentration index, the sequence was intercropped with Trifolium repens > Astrugalus complanatu > Medicago sativa > Lotus comiculotus. The average density of predatory spiders was significant higher (P < 0.05) than that of predatory insects in all test jujube orchards. The individuals of Coccinellidae, Pentatomidae, inoccllidae, Chrysopidae, Thomisidae, Araneidae and Phytoseiidae played the dominant role in the community.