[Effects of foliar spraying with low concentration NaCl on the growth and physiological responses of cucumber seedlings under temperature regulation in solar greenhouse]. / 设施调温模式下叶施低浓度NaClå¯¹é»„ç“œå¹¼è‹—ç”Ÿé•¿å’Œç”Ÿç†æŒ‡æ ‡çš„å½±å“.

In order to clarify the effects of foliar spraying the solution with low concentration NaCl on the growth and matter accumulation of vegetables under the temperature-regulated solar greenhouse, we carried out an experiment on cucumber seedlings with two cotyledons, under two tempera-ture regimes and four concentrations of NaCl. Low-medium temperature zone (L) and medium-high temperature zone (H) were set by low tunnel with plastic film in the greenhouse. The solutions with different concentrations of NaCl, 0 mmol·L-1 (L0 and H0), 5 mmol·L-1 (L5 and H5), 10 mmol·L-1 (L10 and H10) and 15 mmol·L-1 (L15 and H15), were sprayed every day to the cucumber seedlings. The seedling growth, plant biomass, nutrient accumulation and photosynthetic gas exchange parameters of cucumber seedlings were measured at the 21th day of spraying treatment. Compared with the control groups (L0 and H0), NaCl spraying significantly increased dry matter and plant water content by 38.6% (L5)-50.2% (L10) and 20.8% (L5)-52.2% (L10) in L zone, 8.9% (H5)-23.3% (H10) and 8.7% (H5)-10.1% (H10) in H zone, respectively. The treatment of 10 mmol·L-1 NaCl (L10 and H10) under both temperature regimes increased dry matter accumulation and plant water content than other treatments. Nevertheless, the highest normalized strong seedling index (SI) with the highest stomatal conductance (gs) and photosynthetic rate (Pn) was only found in L5 treatment. L10 treatment promoted foliar expansion much more than H10 treatment. In addition, foliar spraying NaCl with concentrations from 5 mmol·L-1 to 10 mmol·L-1 under both temperature regimes significantly increased the accumulation of soluble sugar, free amino acids and soluble protein, which were preferentially allocated to the stem or root of cucumber seedlings. Results of two-way ANOVA showed significant effects of both temperature and NaCl concentration on dry biomass, leaf area, Pn, plant water content, SI, gs and free amino acid content. On the contrary, there were significant interactions between temperature and NaCl concentration in affecting plant water content, SI, gs and free amino acid content (except leaf). In conclusion, foliar spraying with 5-10 mmol L-1 NaCl could promote growth and physiological indices of cucumber seedlings, with the effect being higher under low temperature regime. More importantly, foliar spraying of proper concentration (L5 and H10) of NaCl could stimulate biomass accumulation more than water retention in cucumber seedlings, which would provide a relevant breeding target for high water-use efficiency in cucumber.

miR-93-5p Transferred by Exosomes Promotes the Proliferation of Esophageal Cancer Cells via Intercellular Communication by Targeting PTEN.

OBJECTIVE: To investigate the relationship between plasma miR-93-5p and the risk of esophageal cancer, as well as the influence of miR-93-5p on the biological function of esophageal cancer cells, exerted through exosomes. METHODS: The expression of plasma miR-93-5p in esophageal cancer patients and healthy controls was analysed by real-time quantitative PCR. The influence of miR-93-5p on the risk and prognosis of esophageal carcinoma was analyzed by conditional logistic regression and survival analysis. The effect of miR-93-5p on the biological function of recipient cells was investigated by establishing an in vitro donor cell co-culture model. The target gene of miR-93-5p was validated by luciferase reporter assay and Western Blotting. RESULTS: Upregulation of plasma miR-93-5p expression significantly increases the risk of esophageal cancer and is associated with poor prognosis. miR-93-5p transferred by exosomes promotes the proliferation of recipient esophageal cancer cells and affects the expression of PTEN and its downstream proteins p21 and cyclin D1. CONCLUSION: Our study provides a reference for the identification of biomarkers for the diagnosis and prognosis of esophageal cancer.

[Effects of bagging on light use efficiency of tomato fruit photosystem II].

In a greenhouse experiment, white laminating bags were applied to bag the tomato cultivar 'Baoluota' fruits, with the absorption spectra and chlorophyll fluorescence parameters of the fruits measured by optical spectrometer and Mini-Imaging-Pam after different bagging time, aimed to investigate the effects of bagging on the light use efficiency of photosystem II of the fruits. In the first 20 days of bagging, no significant effects of bagging were observed on the chlorophyll a (Chl a) content and the maximum quantum yield of PS II (Fv/Fm) of the fruits, but the relative absorption coefficient (A(670/780)) and the effective quantum yield of PS II (Y(II)) were reduced, compared with the control. In this period, the regulatory energy dissipation of PS II played, an important role. After then, the Chl a and Chl b contents of bagged fruits decreased markedly, but the Fv/Fm, Y(II), and A(670/780) had no significant differences with the control. On the 40th day of bagging, the Chl a and Chl b contents of bagged fruits decreased by 35.2% and 52.8%, but the Fv/Fm and Y(II) increased by 24.5% and 35.4%, respectively, suggesting that at this time, the PS II of bagged tomato fruits had a higher light use efficiency, which provided energy foundation for the earlier ripening of the bagged fruits via further reducing the quantum yield of non-regulatory energy dissipation (Y(NO)).

[Toxicological effects of omethoate on leaf photosystem II of cole].

After spraying different concentrations of two brands pesticide omethoate on cole (Brassica campestris L.) leaves, the leaf chlorophyll a fluorescence transients were measured by a Plant Efficiency Analyzer (PEA), and the toxicological effects and rudimental dynamic courses of omethoate on the leaf photosystem II (PS II) were investigated by JIP-test. The results showed that after spraying omethoate except at the concentration of 0.50% , the maximal efficiency of photochemistry (F(v)/F(m)) did not have a remarkable change. However, with increasing omethoate concentration, the minimal fluorescence F(o), maximal fluorescence F(m), relative variable fluorescence at the J-step (V(J)), and electron transport flux perreactive center in PS II (ET(o)/RC) increased remarkably, but psi(o), the efficiency that a trapped exciton in PS ]I moved an electron into the electron transport chain beyond Q(A)-, decreased remarkably. The test two brands of pesticide omethoate had almost alike effects on the PS II of cole, and the residual effect of the pesticide was the strongest at the third day after spraying and petered out from the ninth to twelfth day. The main targets of omethoate on the PS II of cole could be listed as promoting the reduction from Q(A) to Q(A) (-) (increasing of V(J)) and the electron transmission from Q(A) (-) to Q(B) (increasing of ET(o)/RC).

[Heat stress characteristics of photosystem II in eggplant].

With lower-and higher heat-resistant varieties of eggplant (Solanum melongena L.) Heibei I and Heibei II as test materials, and by using Plant Efficiency Analyzer (PEA) from Hansatech, this paper measured the fast chlorophyll a fluorescence transient and its parameters. The results showed that PS II construction became more sensitive to heat stress when ambient temperature was higher than 40 degrees C. The F0 went up slowly, and Fv/Fm and deltaF/Fm' came down dramatically. Heibei II had a longer semi-attenuation temperature of Fv/Fm (T50) and deltaF/Fm' (t50) than Heibei I. Under strong heat stress (5 min at 48 degrees C or 20-30 min at 44 degrees C), the K-step in relation to the inactivation of oxygen-evolving complex appeared in fluorescence rise at about 700 micros, and the regular O-J-I-P transient was transformed to O-K-J-I-P one. The K-phase of Heibei I and Heibei II appeared when the treatment time was up to 20 and 30 minutes at 44 degrees C, respectively. In comparing with 35 degrees C heat treatment, the DI0/RC in the parameters of Strasser's specific energy fluxes model was increased by a great extent under 48 degrees C or more heat stress, reflecting a strong safeguard of energy dissipation to PS II. When the temperature of heat stress increased from 35 degrees C to 52 degrees C, the Fvi/Fv of PS II silent reaction centers of Heibei I and Heibei II increased remarkably.