Overexpression of the kiwifruit SVP3 gene affects reproductive development and suppresses anthocyanin biosynthesis in petals, but has no effect on vegetative growth, dormancy, or flowering time

SVP-like MADS domain transcription factors have been shown to regulate flowering time and both inflorescence and flower development in annual plants, while having effects on growth cessation and terminal bud formation in perennial species. Previously, four SVP genes were described in woody perennial vine kiwifruit (Actinidia spp.), with possible distinct roles in bud dormancy and flowering. Kiwifruit SVP3 transcript was confined to vegetative tissues and acted as a repressor of flowering as it was able to rescue the Arabidopsis svp41 mutant. To characterize kiwifruit SVP3 further, ectopic expression in kiwifruit species was performed. Ectopic expression of SVP3 in A. deliciosa did not affect general plant growth or the duration of endodormancy. Ectopic expression of SVP3 in A. eriantha also resulted in plants with normal vegetative growth, bud break, and flowering time. However, significantly prolonged and abnormal flower, fruit, and seed development were observed, arising from SVP3 interactions with kiwifruit floral homeotic MADS-domain proteins. Petal pigmentation was reduced as a result of SVP3-mediated interference with transcription of the kiwifruit flower tissue-specific R2R3 MYB regulator, MYB110a, and the gene encoding the key anthocyanin biosynthetic step, F3GT1. Constitutive expression of SVP3 had a similar impact on reproductive development in transgenic tobacco. The flowering time was not affected in day-neutral and photoperiod-responsive Nicotiana tabacum cultivars, but anthesis and seed germination were significantly delayed. The accumulation of anthocyanin in petals was reduced and the same underlying mechanism of R2R3 MYB NtAN2 transcript reduction was demonstrated.

Effect of nitrogen and potassium fertilisation on vegetative growth and flowering of mature carob trees (Ceratonia siliqua): variations in leaf area index and water use indices

This work aimed to assess how potassium (K) and nitrogen (N) fertilisation may affect the use of precipitation in terms of vegetative and flowering response of 15-year-old carob trees during a 3-year experiment. A field trial was conducted in 1997, 1998 and 1999 in Algarve (Southern Portugal) in a calcareous soil. Four fertilisation treatments were tested: no fertiliser (control); 0.8 kg N/tree (N treatment); 1 kg K 2 O/tree (K treatment) and 0.8 kg N/tree plus 1 kg K 2 O/tree (NK treatment). No irrigation was applied during the experimental period. Branch length increments were measured every month throughout the growing season and inflorescence number was registered once per year. There was a strong seasonal effect on vegetative growth, since low levels of precipitation (115 mm) during October 1998–March 1999 suppressed the increment in branch length. N supplied to the trees (N and NK treatments) tended to increase water use indices in terms of vegetative growth. No response to K alone was observed in trees fertilised only with K. The number of inflorescences increased throughout the experimental period, particularly for N and NK treatments, and a reduction of the precipitation amount during April, May and June, may also enhance flowering. This knowledge could be important when making decisions concerning fertilisation under dry conditions. The results reported here indicate that tree growth (expressed as the branch growth) and flower production under dry-farming conditions, may be achieved by applying 0.8 kg of N (as ammonium nitrate) per tree during the growing season. However, N uptake and use depends on soil water availability.

The effects of temperature and light integral on early vegetative growth and chlorophyll fluorescence of four contrasting genotypes of cacao (Theobroma cacao)

The effect of temperature on early vegetative growth, leaf chlorophyll fluorescence and chlorophyll content was examined on four genotypes of cacao (Amelonado, AMAZ 15–15, SCA 6 and SPEC 54/1). A controlled environment glasshouse was used to simulate the temperature conditions of three cacao-growing regions (Bahia, Brazil; Tafo, Ghana and Lower Perak, Malaysia) over the course of a year. Base temperatures calculated from increments in main stem growth varied from 18.6°C for AMAZ 15/15 to 20.8°C for SPEC 54/1. Temporal variation in Fv/Fm observed for two of the clones (SCA 6 and SPEC 54/1) in two of the compartments were correlated with temperature differences over time. Significant differences were also recorded between genotypes in leaf chlorophyll content. It was shown that variation over time in leaf chlorophyll content could be quantified accurately as a function of temperature and light integral. The results imply that genetic variability exists in cacao in response to temperature stress.

The effect of temperature, photosynthetic photon flux density, and photoperiod on the vegetative growth and flowering of 'Autumn Bliss' raspberry

The effects of temperature, photosynthetic photon flux density (PPFD) and photoperiod on vegetative growth and flowering of the raspberry (Rubus idaeus L.) 'Autumn Bliss' were investigated. Increased temperature resulted in an increased rate of vegetative growth and a greater rate of progress to flowering. Optimum temperatures lay in the low to mid 20degreesC range. Above this the rate of plant development declined. Increased PPFD also advanced flowering. While photoperiod did not significantly affect the rate of vegetative growth, flowering occurred earliest at intermediate photoperiods and was delayed by extreme photoperiods. These responses suggest that there is potential for adjusting cropping times of raspberry grown under protection by manipulating the environment, especially temperature.

Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

Seasonal changes in vegetative growth and photosynthesis of Arabica coffee trees

Seasonal changes in vegetative growth, leaf gas exchanges, carbon isotope discrimination (Delta) and carbohydrate status were monitored in de-fruited coffee trees (Coffea arabica L.) grown in the field, from October 1998 through September 1999, in Vicosa (20degrees45'S, 42degrees15'W, 650 m a.s.l.), southeastern Brazil. of the total growth over the 12-month study period, 78% occurred in the warm, rainy season (October-March), and 22% during the cool, dry season (April-September). Throughout the active growth period, the rate of net carbon assimilation (A) averaged 8.6 mumol m(-2) s(-1), against 3.4 mumol m(-2) s(-1) during the period of reduced growth. In the active period, growth, unlike A or Delta, was strongly negatively correlated with air temperature. In contrast, growth and A were both correlated positively, and Delta correlated negatively, with air temperature during the reduced growth period. However, the depressions of A and growth might have simply run in parallel, without any causal relationship. Changes in A appeared to be largely due to stomatal limitations in the active growing season, with non-stomatal ones prevailing in the slow growth period. Foliar carbohydrates seemed not to have contributed appreciably to changes in growth rates and photosynthesis. (C) 2004 Elsevier B.V. All rights reserved.

The effect of gene tubC on the vegetative growth of benomyl-resistant strains of Aspergillus nidulans

Two benomyl-resistant mutants, benD3 tubC41 and benD4 tubC42, of Aspergillus nidulans were isolated after UV treatment. The tubC mutations permitted good conidiation of these strains in culture media containing benomyl and were responsible for increasing their benomyl resistance levels. This implies that β3-tubulin, a product of the tubC gene, in addition to being involved in fungal conidiation, participates in the vegetative growth of the fungus. The tubC gene was located in linkage group I.

Plant regulators on vegetative growth of 'Tommy Atkins' mangoes

Paclobutrazol applied to the soil is used for the production management of mango in most of orchards on the semiarid region. However, it is necessary to identify other plant growth regulators that might be applied to the leaves, so as to minimize the risk of residues in the soil and plant. The present paper has the purpose to evaluate the effect of plant regulators in the management of vegetative growth on mangoes 'Tommy Atkins'. Three plant growth regulators, sprayed to the leaves, were evaluated: prohexadione-Ca, ethyl-trinexapac and chlormequat chloride, applied in two dosages, and compared to paclobutrazol applied to the soil. In order to compare the effects of the treatment, data were recorded on the vegetative growth (number and length of the shoots). Furthermore, the levels of gibberellins in the apical area of the shoots of 'Tommy Atkins' were quantified, from the beginning of the experiment until the beginning of floral induction. The results showed that sprayings with prohexadione-Ca, trinexapac-ethyl and chlormequat chloride in a dosage of 1.5 g a.i. plant-1 plant was as efficient as a dose of 4.0 g a.i. plant-1 of paclobutrazol applied to the soil, regarding the regulation of vegetative growth of 'Tommy Atkins'. © ISHS 2013.

Elevated pCO2 from late summer coastal upwellings in the western Baltic Sea enhances vegetative growth in the brown algae Fucus serratus: a laboratory assessment

The brown algae Fucus serratus is one of the major meadow forming algae of the Western Baltic Sea nearshore ecosystem. At the end of summer, those meadows are exposed to local upwelling suddenly increasing the pCO2 and DIC up to 2500 µatm and 2250 µmol/kg resp., for period of days to weeks. This study investigates the growth response of summer's vegetative Fucus serratus to elevated pCO2 (1350 and 4080 µatm) during a 40 days laboratory incubation. After 10 days, increases of growth rates of 20 % and 47 % of the control were observed in the 1350 and 4080 µatm pCO2 treatments respectively. Beyond 20 days, the growth rates collapsed in all treatments due to nutrients shortage, as demonstrated by high C:N ratios (95:1) and low N tissue content (0.04 % of dry weight). The collapse occurs faster at higher pCO2. On day 30, growth rates were reduced by 40 % and 100 % relative to the control at 1350 and 4080 µatm respectively. These results are consistent with a fertilizing effect of elevated pCO2 on Fucus serratus presumably linked to the transition from active HCO3- to passive CO2(aq) uptake. This positive effect is limited by nutrients resources, low seawater dissolved inorganic N and P and shortage of the nutrients reserves accumulated over the previous autumn and winter.

The MAPKKK Ste11 regulates vegetative growth through a kinase cascade of shared signaling components

In haploid Saccharomyces cerevisiae, the mating and invasive growth (IG) pathways use the same mitogen-activated protein kinase kinase kinase kinase (MAPKKKK, Ste20), MAPKKK (Ste11), MAPKK (Ste7), and transcription factor (Ste12) to promote either G1 arrest and fusion or foraging in response to distinct stimuli. This exquisite specificity is the result of pathway-specific receptors, G proteins, scaffold protein, and MAPKs. It is currently not thought that the shared signaling components function under the basal conditions of vegetative growth. We tested this hypothesis by searching for mutations that cause lethality when the STE11 gene is deleted. Strikingly, we found that Ste11, together with Ste20, Ste7, Ste12, and the IG MAPK Kss1, functions in a third pathway that promotes vegetative growth and is essential in an och1 mutant that does not synthesize mannoproteins. We term this pathway the STE vegetative growth (SVG) pathway. The SVG pathway functions, in part, to promote cell wall integrity in parallel with the protein kinase C pathway. During vegetative growth, the SVG pathway is inhibited by the mating MAPK Fus3. By contrast, the SVG pathway is constitutively activated in an och1 mutant, suggesting that it senses intracellular changes arising from the loss of mannoproteins. We predict that general proliferative functions may also exist for other MAPK cascades thought only to perform specialized functions.

A Modulatory Role for Clathrin Light Chain Phosphorylation in Golgi Membrane Protein Localization during Vegetative Growth and during the Mating Response of Saccharomyces cerevisiae

The role of clathrin light chain phosphorylation in regulating clathrin function has been examined in Saccharomyces cerevisiae. The phosphorylation state of yeast clathrin light chain (Clc1p) in vivo was monitored by [32P]phosphate labeling and immunoprecipitation. Clc1p was phosphorylated in growing cells and also hyperphosphorylated upon activation of the mating response signal transduction pathway. Mating pheromone-stimulated hyperphosphorylation of Clc1p was dependent on the mating response signal transduction pathway MAP kinase Fus3p. Both basal and stimulated phosphorylation occurred exclusively on serines. Mutagenesis of Clc1p was used to map major phosphorylation sites to serines 52 and 112, but conversion of all 14 serines in Clc1p to alanines [S(all)A] was necessary to eliminate phosphorylation. Cells expressing the S(all)A mutant Clc1p displayed no defects in Clc1p binding to clathrin heavy chain, clathrin trimer stability, sorting of a soluble vacuolar protein, or receptor-mediated endocytosis of mating pheromone. However, the trans-Golgi network membrane protein Kex2p was not optimally localized in mutant cells. Furthermore, pheromone treatment exacerbated the Kex2p localization defect and caused a corresponding defect in Kex2p-mediated maturation of the α-factor precursor. The results reveal a novel requirement for clathrin during the mating response and suggest that phosphorylation of the light chain subunit modulates the activity of clathrin at the trans-Golgi network.

Modeling chickpea growth and development: Nitrogen accumulation and use

Quantitative information regarding nitrogen (N) accumulation and its distribution to leaves, stems and grains under varying environmental and growth conditions are limited for chickpea (Cicer arietinum L.). The information is required for the development of crop growth models and also for assessment of the contribution of chickpea to N balances in cropping systems. Accordingly, these processes were quantified in chickpea under different environmental and growth conditions (still without water or N deficit) using four field experiments and 1325 N measurements. N concentration ([N]) in green leaves was 50 mg g-1 up to beginning of seed growth, and then it declined linearly to 30 mg g-1 at the end of seed growth phase. [N] in senesced leaves was 12 mg g-1. Stem [N] decreased from 30 mg g-1 early in the season to 8 mg g-1 in senesced stems at maturity. Pod [N] was constant (35 mg g-1), but grain [N] decreased from 60 mg g-1 early in seed growth to 43 mg g-1 at maturity. Total N accumulation ranged between 9 and 30 g m-2. N accumulation was closely linked to biomass accumulation until maturity. N accumulation efficiency (N accumulation relative to biomass accumulation) was 0.033 g g-1 where total biomass was -2 and during early growth period, but it decreased to 0.0176 g g-1 during the later growth period when total biomass was >218 g m-2. During vegetative growth (up to first-pod), 58% of N was partitioned to leaves and 42% to stems. Depending on growth conditions, 37-72% of leaf N and 12-56% of stem N was remobilized to the grains. The parameter estimates and functions obtained in this study can be used in chickpea simulation models to simulate N accumulation and distribution.

Growth of and trehalase activity in the thermophilic fungusThermomyces lanuginosus

The thermophilic fungus,Thermomyces lanuginosus, was grown in a glucose-asparagine liquid medium. Optimal mycelial growth occurred at 50°C. The conditions for sporulation were different from those required for vegetative growth. the former being favoured by lower nitrogen level and temperature. Trehalase (α, α-glu coside-l-glucohydrolase, EC 3.2.1.28) was one of the most active glycosidases at 50°C. Non-sporulating mycelium had higher levels of this enzyme than the sporulating mycelium. Trehalase was synthesized constitutively and its activity appears to be controlled by catabolite repression.

Effect of plant density and initial crown size on growth, development and yield in strawberry cultivars Elsanta and Bolero

The effects of density (plant spacing) and initial plant size on vegetative growth, flowering and fruiting were studied in the strawberry cultivars Elsanta and Bolero in their first and second years of cropping. The influence of these factors on light use and dry-matter partitioning was investigated. The size of planting material in 'Elsanta' and 'Bolero' slightly affected plant growth and yield, but this effect was not consistent and radiation use efficiency (RUE) and harvest index were unaltered. Plant spacing did not significantly affect the early stages of crop growth, but was important in determining growth and yield later in the season, this effect being more significant in the second year of cropping. Plant growth and yield per plant increased as plant spacing increased from 20 to 30 cm in both 'Elsanta' and 'Bolero', but the highest harvest index and yield per square metre were obtained at the closest spacing. Increased plant spacing also resulted in a greater leaf area and leaf area index. However, light was used less efficiently resulting in a lower RUE and lower harvest index (HI).

Regulated deficit irrigation - a means to control growth in woody ornamentals

Improving plant quality and the uniformity of a crop are major objectives for growers of ornamental nursery stock. The potential to control excess vigour and to improve quality through regulated deficit irrigation (RDI) was investigated using a range of woody ornamental species. RDI regimes reduced vegetative growth consistently across different species and growing seasons. Plants adapted to reduced water supplies primarily via stomatal control, but also by osmotic adjustment when grown under the most severe RDI regimes. Only plants exposed to <= 25% of potential evapo-transpiration demonstrated any evidence of leaf injury, and the extent was slight. Growth inhibition increased as the severity of RDI increased. Improvements in quality were attained through a combination of shorter internodes and final shoot lengths, yet the number of 'formative' primary shoots remained unaffected. Compact, well-branched plants could be formed without a requirement for mid-season pruning. In addition to severity, the timing of RDI also influenced growth responses. Applying 50% ETp for 8 weeks during July-August resulted in the formation of good quality plants, which retained their shape until the following Spring. Re-positioning irrigation drippers within the pots of well-watered plants, in an attempt to induce a partial root drying (PRD) treatment, reduced growth, but not significantly. The adoption of irrigation scheduling, based on 50-100% ETp, has the potential to improve commercial crop quality across a range of ornamental species.