Summary
A group of MADS transcription factors (TFs) are believed to control temperature‐mediated bud dormancy. These TFs, called DORMANCY‐ASSOCIATED MADS‐BOX (DAM), are encoded by genes similar to ...SHORT VEGETATIVE PHASE (SVP) from Arabidopsis. MADS proteins form transcriptional complexes whose combinatory composition defines their molecular function. However, how MADS multimeric complexes control the dormancy cycle in trees is unclear.
Apple MdDAM and other dormancy‐related MADS proteins form complexes with MdSVPa, which is essential for the ability of transcriptional complexes to bind to DNA. Sequential DNA‐affinity purification sequencing (seq‐DAP‐seq) was performed to identify the genome‐wide binding sites of apple MADS TF complexes. Target genes associated with the binding sites were identified by combining seq‐DAP‐seq data with transcriptomics datasets obtained using a glucocorticoid receptor fusion system, and RNA‐seq data related to apple dormancy.
We describe a gene regulatory network (GRN) formed by MdSVPa‐containing complexes, which regulate the dormancy cycle in response to environmental cues and hormonal signaling pathways. Additionally, novel molecular evidence regarding the evolutionary functional segregation between DAM and SVP proteins in the Rosaceae is presented.
MdSVPa sequentially forms complexes with the MADS TFs that predominate at each dormancy phase, altering its DNA‐binding specificity and, therefore, the transcriptional regulation of its target genes.
Geneva® rootstocks in Brazil are known to be efficient in controlling vigor, and are precocious and resistant to diseases. The objective of this study was to evaluate the performance of apple tree ...cultivars grafted on the Geneva® rootstocks in severe replant disease areas, by planting 60 days after the eradication. The experiments were implemented in 2017, in São Joaquim and Vacaria. The Gala Select and Fuji Suprema cultivars were grafted onto ‘G.202’, ‘G.814’, ‘G.210’, and ‘G.213’ rootstocks in the Tall Spindle training system. In 2018/2019, total thinning was carried out to promote plant growth. In São Joaquim, partial thinning was carried out in 2019/2020 harvest of ‘Gala Select’. The rootstocks were divided into two groups based on vigor, for both areas and cultivars. ‘G.202’ and ‘G.213’ were 40% less vigorous than ‘G.210’ and ‘G.814’. For ‘Gala Select’, the extreme non-fallow condition mainly affected the vigor and productivity of ‘G.213’ in both areas. At the end of two harvests, ‘G.213’ was 17% less productive than ‘G.210’, contrary to what is observed in areas where the fallow period is respected. However, ‘G.213’ confirmed a greater yield efficiency, which was 27% higher than ‘G.210’. This suggests that a perspective of forecasting production for the third crop is higher for ‘G.213’ than for ‘G.210’. In the case of ‘Fuji Suprema’, the G.210 rootstock was the most productive in both areas. In São Joaquim, ‘G.202’ matched ‘G.210’ in productivity and efficiency as it sprouts better in colder regions. Considering the fruit quality, ‘G.213’ anticipated the maturation with fruits of larger size and higher total soluble solids (TSS) in both areas and cultivars, making it possible to anticipate the harvest. It was concluded that the non-fallow condition does not alter the relative differences in vigor and fruit quality among the rootstocks. However, notwithstanding the overall replant tolerance of these rootstocks, it does reduce productivity by mainly affecting less vigorous rootstocks that need about three crops to overcome the allelopathic effects of the soil and start growing normally. The G.210 semi-dwarfing rootstock is an alternative for the immediate conversion of apple orchards of Gala Select and Fuji Suprema cultivars in southern Brazil.
The apple tree is the most common fruit crop in the temperate climate zone. Modern intensive fruit cultivation involves the use of new, highly productive cultivars and cultivation technologies, ...thanks to the creation of small crown shapes with an increased number of trees per hectare. Reducing planting patterns and creating more dense plantation systems can significantly improve their yields. However, the limiting factor that can reduce tree productivity and deteriorate fruit quality is the degree of crown illumination. Ensuring even access of sunlight to all parts of the crown is the main task in the formation and pruning trees. The study aimed to determine the effect of crown pruning at BBCH 0 (winter) and BBCH 74 (early summer) and various types of crown formation on the growth activity and productivity of ‘Fuji’ and ‘Honeycrisp’ apple trees. A significant decrease (20%) in the number of newly formed shoots in the form of the French axis crown compared to the ballerina and slender spindle crowns was found. However, their length and total growth were significantly higher. The formation of the ballerina crown (with the removal of overgrown wood in the 25 cm zone on the central conductor above the lower tier of semi-cross-branched branches) contributed to a decrease in shoot length and total growth. The introduction of crown pruning in the summer also improved crown illumination – shoot length decreased by 17% and total growth by 12%. Specific productivity per bole cross-section and total shoot length was the highest in ballerina crown trees, followed by trees with a slender spindle crown, and trees pruned in winter and summer.
Display omitted
•Methylene Blue and Janus Green B were rapidly removed by ZnS:Ni-NPs-ACATW.•Dyes removal from aqueous solution was demonstrated.•In the optimization step, response surface methodology ...was utilized as a design of experiment method.•A maximum MB and JGB removal (99.57%±1.34 and 98.70%±2.01, respectively) were recorded.
The applicability of ZnS:Ni nanoparticles loaded on activated carbon derived from apple tree wood (ZnS:Ni-NPs-ACATW) for the adsorption of Methylene Blue (MB) and Janus Green B (JGB) dyes in single system from water solution has been described. The synthesized adsorbent characterized and identified by UV–Vis, FE-SEM, EDX, TEM, FTIR and XRD. The influences of operation parameters including initial MB or JGB concentration (9.0–33.0mgL−1), pH (4.0–10.0), extent of adsorbent (0.08–0.12g) and sonication time (4.0–8.0min) investigated and subsequently best operational condition optimized by central composite design (CCD) combined with response surface methodology (RSM) and desirability function (DF) using STATISTICA 10.0 software. At optimum conditions, maximum MB and JSB adsorption onto ZnS:Ni-NPs-ACATW, i.e. 99.57%±1.34 and 98.70%±2.01, respectively was achieved pH of 7.0, 0.11g adsorbent, 14 and 28mgL−1 of MB and JSB concentration respectively and 8min sonication time. Experimental data were modelled by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherms. Langmuir isotherm and monolayer adsorption capacity of MB and JSB was found to be 21.79 and 28.01mgg−1 respectively. The regression results strongly support more contribution of pseudo-second-order model for more accurate and repeatable representation of kinetic data. These results reveal that ZnS:Ni-NPs-ACATW could be useful as agents to efficiently remove dyes (JGB and MB) from contaminated water and can be very well recommended for wastewater remediation and control of environmental pollution.
•A dielectric sensor with interdigitated-electrodes (IE) is developed to measure StWC.•Assess E-field distributions of the IE sensor and an existing dielectric sensor.•The IE sensor has higher ...sensitivity to StWC measurement than the existing sensor.•The IE sensor is less susceptible to stem diameter variation than the existing sensor.•The IE sensor provides accurate, in-situ, measurement under water deficit condition.
Stem water content (StWC) of plants is an important parameter for assessing plant response to drought stress in arid and semi-arid areas and for irrigation scheduling. The measurement accuracies of in-situ non-invasive approaches are degraded by plant growth and by diurnal changes in stem diameter associated with water content. Here we develop a frequency-domain (FD) dielectric sensor operating at 100 MHz with an innovative interdigitated-electrodes (IE) probe design for measuring StWC. We characterize the performance of the IE sensor and compare it with a previously described pair-strap-ring-electrodes (2RE) FD sensor. Simulations and experimental measurements were conducted to assess the electric field distribution and volume of sensitivity (VOS) of each probe, the sensitivity of each probe to stem diameter and the accuracy of each sensor for determining StWC of three apple trees in a greenhouse environment. The simulation analysis and the measurement showed that the IE probe has a smaller but denser VOS than the 2RE probe. The sensitivity test showed that the new IE probe (0.85 mV mm−1, R2 = 0.7108) was less susceptible to stem diameter variation in comparison with the 2RE probe (32.83 mV mm−1, R2 = 0.9977). The observations in the greenhouse showed that the three apple trees (AT-1, AT-2 and AT-3) experienced a daily dehydration-rehydration cycle and the averaged midnight-to-predawn StWC gradually decreased without irrigation. According to the reference values of the maximum daily trunk shrinkage (MDS) reported by a previous study, both AT-2 and AT-3 may experience water deficit before the irrigation. Besides, the stem diameter variation decreased the measurement accuracy of 2RE sensor to be ~0.0410 cm3 cm−3 mm−1. The stronger electric field intensity of the IE probe and its less susceptible to stem diameter variation make the new IE dielectric sensor an improved method for accurate in-situ measurement of diurnal stem water content.
Accurate and rapid diagnosis of nitrogen status in fruit trees on an individual tree basis is a prerequisite for precision orchard nutrient management. This study presents a rapid and non-destructive ...approach for estimation and mapping of nitrogen content in apple trees at both leaf and canopy levels. An ImSpector V10 system was used to collect hyperspectral images (400–1000 nm) for both apple leaves and canopies. Nitrogen content in apple leaves was measured by Vario EL cube. Raw reflectance and first derivative reflectance were used to relate to leaf nitrogen content. Partial least squares (PLS) regression and multiple linear regression (MLR) analyses were performed to estimate nitrogen content from reflectance. The results showed that both PLS and MLR models achieved reasonable predictive accuracy (PLS and MLR models based on raw reflectance: R
2
= 0.7728 and 0.7843 (p < 0.001); PLS and MLR models based on first derivative reflectance: R
2
= 0.7745 and 0.774 (p < 0.001)). However, the MLR model based on raw reflectance demonstrated its advantage over the PLS models as well as the MLR model based on first derivative reflectance, because it only used 4 key wavelengths (505, 560, 675 and 705 nm) while the other models were based on either the full wavelengths (132 wavelengths) or more narrowband wavelengths adjacent to the selected key wavelengths. Furthermore, nitrogen distribution maps at both leaf and canopy levels were generated based on the nitrogen contents estimated by the MLR model based on raw reflectance. This new approach may be potentially applied to precision apple orchard nutrient management.
We monitored the levels of cesium-137 (137Cs) in the soils of five orchards for six years following the Fukushima Daiichi Nuclear Power Plant accident on 11 March 2011 and found that the vertical ...distribution of accident-derived 137Cs varied significantly among the orchards with varying land-use and fertilizer management. Based on these results, this study evaluated how nitrogen (N) fertilizer management may have affected the vertical migration of 137Cs in the orchard soils. We selected an experimental orchard producing ‘Jonathan’ apples, where a long-term N-fertilizer trial has continued since 1973, with an N-fertilized plot (N plot; N added at 20 g m−2 y−1) and a non-fertilized plot (0 N plot). Five years after the accident, the vertical migration of accident-derived 137Cs was significantly lower in the N plot (2.3 cm) than in the 0 N plot (4.3 cm), suggesting greater 137Cs retention in the surface of the N plot. Application of a cesium bromide (133CsBr) tracer suggested that the retarded vertical migration of 137Cs in the N plot may be related to significantly lower amounts of exchangeable 133Cs and significantly higher proportions of non-exchangeable 133Cs in the upper 2 cm. We did not find any evidence of the aboveground plants contributing to more 133Cs retention in the N plot. However, greater 137Cs retention in the surface (0–2 cm) of the N plot may be due to more dissolved organic carbon (DOC), and high DOC may have contributed to deeper 137Cs migration in both the plots. Our results suggest that continuous N fertilizer application significantly retarded the migration of 137Cs by approximately one-half and resulted in less 137Cs reaching the mobile exchangeable form in the deeper root-zone layers.
Display omitted
•Orchard topsoil retained 42–83% of 137Cs from the Fukushima accident after 5 years.•Long-term N fertilization reduced the soil 137Cs migration rate by about one-half.•N fertilization resulted in less Cs with mobile exchangeable form at the surface.•Reduced 137Cs migration may be due to higher fixation at the surface.•N fertilization may reduce radiation risk via tree roots by slowing 137Cs migration.
, a parasitic fungus, is a destructive pathogen of apple tree that causes heavy economic losses in China. The pathogen secretes various cell wall-degrading enzymes (CWDEs) that degrade plant ...cell-wall components, and thus facilitate its entry into host cells. Therefore, functional analysis of the genes encoding CWDEs is necessary to understand virulence of
toward apple tree. Here, we identified and cloned an endo-β-1,4-xylanase gene,
in
. The full-length cDNA of
is 1626 bp containing 5'- and 3'-non-coding regions, as well an open reading frame of 1320 bp that encodes a protein with a calculated molecular mass and an isoelectric point of 43.8 kDa and 4.4, respectively. The predicted amino acid sequences showed significant homology to a family GH10 of glycosyl hydrolases. The apple branch extract and beechwood xylan, but not glucose, induced the expression of
. Furthermore,
had high expression levels in the apple tree bark during the pathogen infection. The deletion of
did not affect mycelia growth; however, it significantly reduced pycnidia formation in
. The deletion strains showed a reduced virulence toward apple leaves and twigs. Moreover, the mutant strains had reduced endo-β-1,4-xylanase activity and growth when cultured using beechwood xylan as the only carbon source. Reintroducing wild-type
into the mutant strains rescued the defect phenotype. We conclude that
determines the virulence of
toward apple tree. These results provide valuable insight into the plant-pathogen molecular interactions.
PDF
