Genome-wide analysis of the 6B-INTERACTING PROTEIN1 gene family with functional characterization of MdSIP1-2 in Malus domestica.

Trihelix transcription factors consist of five subfamilies, including GT-1, GT-2, SH4, GTγ, and SIP1, which play important roles in the responses to biotic and abiotic stresses, however, seldom is known about the role of the SIP1 genes in apples. In this study, 12 MdSIP1 genes were first identified in apples by genome-wide analysis, and contained conserved MYB/SANT-like domains. Expression patterns analyses showed that the MdSIP1 genes had different tissue expression patterns, and different transcription levels in response to abiotic stresses, indicating that MdSIP1s may play multiple roles under various abiotic stresses. Among them, the MdSIP1-2 gene was cloned and ectopic transformed into Arabidopsis, and its biology function was identified. The subcellular localization showed that MdSIP1-2 protein was specifically localized in the nucleus, and that overexpression of MdSIP1-2 promoted the development of lateral roots, increased abscisic acid (ABA) sensitivity, and improved salt and drought tolerance. These findings suggested that MdSIP1-2 plays an important role in root development, ABA synthesis, and salt and drought stress tolerance. In conclusion, these results lay a solid foundation for determining the role of MdSIP1 in the growth and development and abiotic stress tolerance of apples.

Effects of Granule Dendrobii on chronic atrophic gastritis induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats.

BACKGROUND: Dendrobium officinale is an herb of Traditional Chinese Medicine (TCM) commonly used for treating stomach diseases. One formula of Granule Dendrobii (GD) consists of Dendrobium officinale and American Ginseng (Radix Panacis quinquefolii), and is a potent TCM product in China. Whether treatment with GD can promote gastric acid secretion and alleviate gastric gland atrophy in chronic atrophic gastritis (CAG) requires verification. AIM: To determine the effect of GD treatment on CAG and its potential cellular mechanism. METHODS: A CAG model was induced by feeding rats N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) for 12 wk. After oral administration of low, moderate, and high doses of GD in CAG rats for 8 wk, its effects on body weight, gastric mucosa histology, mucosal atrophy, intestinal metaplasia, immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and B-cell lymphoma-2, and hemoglobin and red blood cells were examined. RESULTS: The body weights of MNNG-induced CAG model rats before treatment (143.5 ± 14.26 g) were significantly lower than that of healthy rats (220.2 ± 31.20 g, P < 0.01). At the 8th week of treatment, the body weights of rats in the low-, moderate-, and high-dose groups of GD (220.1 ± 36.62 g) were significantly higher than those in the untreated group (173.3 ± 28.09 g, all P < 0.01). The level of inflammation in gastric tissue of the high-dose group (1.68 ± 0.54) was significantly reduced (P < 0.01) compared with that of the untreated group (3.00 ± 0.00, P < 0.05). The number and thickness of gastric glands in the high-dose group (31.50 ± 6.07/mm, 306.4 ± 49.32 µm) were significantly higher than those in the untreated group (26.86 ± 6.41/mm, 244.3 ± 51.82 µm, respectively, P < 0.01 and P < 0.05), indicating improved atrophy of gastric mucosa. The areas of intestinal metaplasia were significantly lower in the high-dose group (1.74% ± 1.13%), medium-dose group (1.81% ± 0.66%) and low-dose group (2.36% ± 1.08%) than in the untreated group (3.91% ± 0.96%, all P < 0.01). The expression of PCNA in high-dose group was significantly reduced compared with that in untreated group (P < 0.01). Hemoglobin level in the high-dose group (145.3 ± 5.90 g/L), medium-dose group (139.3 ± 5.71 g/L) and low-dose group (137.5 ± 7.56 g/L) was markedly increased compared with the untreated group (132.1 ± 7.76 g/L; P < 0.01 or P < 0.05). CONCLUSION: Treatment with GD for 8 wk demonstrate that GD is effective in the treatment of CAG in the MNNG model by improving the histopathology of gastric mucosa, reversing gastric atrophy and intestinal metaplasia, and alleviating gastric inflammation.

Effects of metamitron on fruit set and photosynthetic biological characteristics of apples.

With dwarfing interstock Fuji apples as the test materials and water treatment as the control (CK), we examined the fruit thinning effect and its influences on leaves' photosynthesis by spraying 200, 300, and 400 mg·L-1 metamitron during the young fruit period to solve artificial fruit thinning problems (time-consuming, much labor, and low efficiency). The results showed that metamitron application could significantly reduce the inflorescence and flowers' fruit-setting rate by 16.5%-22.8% and 50.9%-53.9%, respectively. The treatment of 300 mg·L-1 metamitron had the strongest fruit thinning effect, with a single fruit rate of 46.6% and a double fruit rate of 18.3%. As a photosynthesis inhibitor, metamitron application reduced the chlorophyll content of leaves and strongly affected photosynthesis. The inhibitory effect on chlorophyll content disappeared after 15 days of the treatment, while that on the net photosynthetic rate disappeared gradually after 11 days of the treatment. The application of metamitron significantly reduced the maximum quantum yield of PSⅡ reaction center (Fv/Fm), actual photochemical efficiency (ΦPSⅡ), photochemical quenching coefficient (qP) and non-photochemical quenching coefficient (NPQ), with such inhibitory effect having been lasted for 15 days. OJIP analysis showed that metamitron caused damage to the apple leaves' oxygen-evolving complex, especially limiting the transfer of electrons in the PSⅡ reaction center from QA to QB. Metamitron treatment increased Wk, and significantly decreased ψo, RC/CSm, and PIabs. Besides, 300 mg·L-1 metamitron had the most significant effect. Our results showed that metamitron destroyed the structure of the PSⅡ reaction center of apple leaves and hindered the transfer of electrons from the donor to the receptor of PSⅡ. Consequently, the photosynthetic rate was affected, and the young fruits fell off due to the lack of accumulation of photosynthetic products.

Control efficacy of Ca-containing foliar fertilizers on bitter pit in bagged 'Fuji' apple and effects on the Ca and N contents of apple fruits and leaves.

BACKGROUND: The preharvest application of Ca-containing foliar fertilizers can reduce the incidence of bitter pit (BP) in apples and improve fruit quality by increasing the Ca content and decreasing both the N content and the N/Ca ratio in fruits. In this study, we aimed to investigate the control efficacy of Ca-containing fertilizers on the incidence of BP and their effects on the Ca and N contents in bagged 'Fuji' apples by spraying foliar fertilizer containing calcium chloride (CaCl2 ), calcium nitrate [Ca(NO3 )2 ] or calcium formate [Ca(HCOO)2 ] at an early stage, five days after full bloom (DAFB) and 40 DAFB, and at a late stage, 80 DAFB and 125 DAFB. RESULTS: The incidences of BP were reduced significantly by 43.2-73.0%, and the efficacy of spraying at an early stage was significantly higher than that of spraying at a late stage. The Ca content of bagged apple fruits increased whereas the N content and N/Ca ratio decreased after spraying Ca-containing foliar fertilizers; however, the Ca content, N content and N/Ca ratio of apple leaves were differentially influenced. CONCLUSION: Foliar fertilizer containing CaCl2, Ca(NO3 )2 or Ca(HCOO)2 can be used at an early stage to control BP in apple and improve the quality of bagged apple fruits. © 2018 Society of Chemical Industry.