Effects of phosphogypsum on the growth of potato plants overexpressing the StDREB1 transcription factor

We developed an efficient system for agrobacterial transformation of plum (Prunus domestica L.) leaf explants using the PMI/mannose and GFP selection system. The cultivar ‘Startovaya’ was transformed using Agrobacterium tumefaciens strain CBE21 carrying the vector pNOV35SGFP. Leaf explants were placed onto a nutrient medium containing various concentrations and combinations of mannose and sucrose to develop an efficient selection system. Nine independent transgenic lines of plum plants were obtained on a regeneration medium containing 20 g/L sucrose and 15 g/L mannose. The highest transformation frequency (1.40?%) was produced using a delayed selection strategy. Starting from the 1st days after transformation and ending by regeneration of shoots from the transgenic callus, selection of transgenic cells was monitored by GFP fluorescence that allowed avoiding formation of escapes. Integration of the manA and gfp transgenes was confirmed by PCR and Southern blotting. The described transformation protocol using a positive PMI/mannose system is an alternative selection system for production of transgenic plum plants without genes of antibiotic and herbicide resistance, and the use of leaf explants enables retention of cultivar traits of plum plants.     

Impact of chemical elicitor applications on greenhouse tomato plants and population growth of the green peach aphid, Myzus persicae

Recent advances in the understanding of plant signaling pathways have opened the way for using elicitor‐induced plant resistance as a tactic for protecting plants against arthropod pests. Four common elicitors of induced responses in tomato, Lycopersicon esculentum Mill. (Solanaceae), were evaluated with regard to phytotoxicity, induction of plant defensive proteins, and effects on population growth and fecundity of a common pest, the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae). Ethephon and methyl jasmonate (MJ) treatments caused varying degrees of phytotoxicity. Ethephon caused pronounced changes in plant growth form and severe, dose‐dependent negative impacts on plant growth and flowering. Effects with MJ were milder, but still caused temporary inhibition of development, leading to smaller plants and delayed flowering. The commercial elicitors benzothiadiazole (BTH) and harpin did not cause detectable phytotoxicity. The highest doses of ethephon and MJ significantly increased leaf peroxidase (POD) levels but only MJ treatments significantly increased polyphenol oxidase (PPO) levels. BTH and harpin had no detectable effects on POD and PPO. Populations of green peach aphids grew significantly more slowly on plants treated with BTH or MJ than on control plants or plants treated with harpin or ethephon. Slowed aphid population growth on BTH‐treated plants was due to significant reductions in aphid fecundity, although this was independent of changes in time to onset of reproduction or time to death. Aphid fecundity was also reduced on MJ‐treated plants relative to controls, but this difference was not statistically significant, suggesting that other mechanisms are involved in slowing aphid population growth on MJ‐treated plants. Growth of aphid populations on plants treated with a MJ–BTH mixture was reduced almost as much as with treatments of MJ alone, suggesting that antagonism between JA‐dependant and SA‐dependent plant signaling pathways is only mild with regard to induced defenses against aphids.     

Oxidative stress,growth factor production and budding in potato tubers during cold storage

In order to verify the role played by oxidation in the budding of potato tubers (Solanum tuberosum L. cv. Kennebec), the physiological events occurring below bud at 4°C have been studied for a period of 6 months. The low temperature storage induced an increase in the degree of unsaturation and a decrease in the ratio of saturated/unsaturated fatty acids of membrane polar lipids with a subsequent increase of lipid hydroperoxides (LOOH). Cold stress increased both enzymatic antioxidative activities (superoxide dismutase, SOD, E.C.1.15.1.1; catalase, CAT, E.C. 1.11.1.6), and α-tocopherol levels thus protecting membrane's polyunsaturated lipids. Between 0 and 15 days of storage SOD/CAT ratio, α-tocopherol, LOOH levels and the degree of lipid unsaturation showed strong variations. After 30 to 120/150 days the antioxidative system seemed to reach a homeostasis different from that of time 0, accompanied by a constant increase of indole-3-acetic acid (IAA) after 60 days. The antioxidative system, after 150 days, lost its efficiency while LOOH levels were maintained higher than time 0 and IAA concentration was sufficient to allow sprouting.     

Light-induced changes in the lipid composition and ultrastructure of plastids from potato tubers

Sandelius, A. S. and Liljenberg, C. 1982. Light-induced changes in the lipid composition and ultrastructure of plastids from potato tubers. – Physiol. Plant. 56: 266–272.
Amyloplasts and starch containing plastids from green tissue – amylochloroplasts – from potato tubers ( Solanum tuberosum L., var. King Edward) were separated from other cell organelles by sedimentation in a discontinuous sucrose gradient. Their lipid composition was analysed with emphasis on galactolipids and phospholipids and the fatty acid compositions of these lipids. Irradiation of the tubers caused increased ratios of monogalactosyl diacylglycerol to digalactosyl diacylglycerol and of total galactolipids to total phospholipids in the plastid membranes. Furthermore, the degree of unsaturation of the fatty acids increased in all lipid classes analysed, this effect being most prominent in the galactolipids. The ultrastructural studies made on tuber tissue revealed that irradiation caused a change in starch grain size distribution concomitant with formation of membrane structures resembling grana within the envelope. In many cases prolamellar bodies and plastoglobuli were present.     

Oxidative stress, growth factor production and budding in potato tubers during cold storage.

In order to verify the role played by oxidation in the budding of potato tubers (Solanum tuberosum L. cv. Kennebec), the physiological events occurring below bud at 4 degrees C have been studied for a period of 6 months. The low temperature storage induced an increase in the degree of unsaturation and a decrease in the ratio of saturated/unsaturated fatty acids of membrane polar lipids with a subsequent increase of lipid hydroperoxides (LOOH). Cold stress increased both enzymatic antioxidative activities (superoxide dismutase, SOD, E.C.1.15.1.1; catalase, CAT, E.C.1.11.1.6), and alpha-tocopherol levels thus protecting membrane's polyunsaturated lipids. Between 0 and 15 days of storage SOD/CAT ratio, alpha-tocopherol, LOOH levels and the degree of lipid unsaturation showed strong variations. After 30 to 120/150 days the antioxidative system seemed to reach a homeostasis different from that of time 0, accompanied by a constant increase of indole-3-acetic acid (IAA) after 60 days. The antioxidative system, after 150 days, lost its efficiency while LOOH levels were maintained higher than time 0 and IAA concentration was sufficient to allow sprouting.     

Differences in chemical composition of plants grown at constant relative growth rates with stable mineral nutrition

Summary Leaf chemistry of a willow clone (Salix aquatica Smith) differed significantly when grown at constant relative growth rates depending upon the relative availability of nutrients and light. Concentration of amino acids and nitrate were high in plants grown with a relative surplus of nutrients. Concentrations of starch, tannin, and lignin, on the other hand, were high in plants grown with a relative surplus of carbon. Photosynthetic rates, expressed per unit leaf area, were similar when plants were grown under high light conditions, regardless of nutrient availability. Dark respiration was much higher in plants supplied with abundant nutrients than in those with a more limited supply, reflecting differences in nitrogen concentration of the tissue. The experimental approach allows plants to be grown to a standard size with differing, but highly uniform chemistry. Plants grown in such a manner may provide good experimental material to evaluate interactions between herbivores or pathogens and their hosts.     

Susceptibility of potato plants grown from tubers irradiated with stimulation doses of gamma irradiation to potato tuber moth, Phthorimaea operculella Zeller (Lep., Gelechiidae)

The feeding behaviour of potato tuber moth, Phthorimaea operculella Zeller (Lep., Gelechiidae), reared on leaves and tubers of potato plants, which were irradiated as seed (tubers) with stimulation doses of gamma irradiation (1, 3, 5 and 10 Gy), was studied. Significant differences in the larvae and pupae developmental time, pupal weight, mortality, fecundity and percentage egg hatch, were observed between insects fed on plants which resulted from the irradiated seeds and those of the control. It appears that leaves of potato plants grown from irradiated seeds particularly those of 3 Gy, became more attractive to the larvae, although the resulting tubers, with the exception of those of 10 Gy, became more resistant to potato tuber moth. Storing the tubers at ambient temperature conditions affected the degree of larval sensitivity. The leaves and tubers of 10 Gy-irradiated seeds became more suitable for insect development, indicating that the later dose may inhibit the production of secondary plant metabolities and chemical compounds.     

Evaluation of some cereals, plants and tubers through protein composition

Wild and cultivated maize, sorghum, rice, amaranth, soybean, and cassava were screened for variability in seed storage proteins. Total seed proteins, albumin (Alb-1 and Alb-2), globulin, alcohol-soluble (A1 and A2), and glutelin (G1 and G2) fractions were investigated by means of sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE). The comparison was done by the obtained protein patterns and their relative amounts. Using quantitative analysis of the protein composition and the electrophoretic patterns, the relationships between total proteins and amount of individual proteins were determined. Electrophoretic patterns of extracted proteins from investigated samples showed that the main protein subunits were concentrated between 10 and 45 kDa. Variation was found in major fractions and minor bands. Electrophoretic patterns of the protein fractions are directly related to the genetic background of the protein and can be identified and used to certify the genetic makeup of wild, cultivated, or newly derived cereals and plants.     

Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers

Vermicomposts, produced commercially from food wastes, were substituted at a range of different concentrations into a soil-less commercial bedding plant container medium, Metro-Mix 360 (MM360), to evaluate their effects on the growth and yields of peppers in the greenhouse. Six-week-old peppers (Capsicum annum L. var. California) were transplanted into 100%, 80%, 60%, 40%, 20% or 10% MM360 substituted with 0%, 10%, 20%, 40%, 60%, 80% and 100% vermicompost. All plants were watered three times weekly with 200 ppm Peter's Nutrient Solution from the time of transplanting up to 107 days. Peppers grown in potting mixtures containing 40% food waste vermicomposts and 60% MM360 yielded 45% more fruit weights and had 17% greater mean number of fruits than those grown in MM360 only. The mean heights, numbers of buds and numbers of flowers of peppers grown in potting mixtures containing 10-80% vermicompost although greater did not differ significantly from those of peppers grown in MM360. There were no positive correlations between the increases in pepper yields, and the amounts of mineral-N and microbial biomass-N in the potting mixtures, or the concentrations of nitrogen in the shoot tissues of peppers. Factors such as: an improvement of the physical structure of the potting medium, increases in populations of beneficial microorganisms and the potential availability of plant growth-influencing-substances produced by microorganisms in vermicomposts, could have contributed to the increased pepper yields obtained.     

Effect of proteinaceous proteinase inhibitors from potato tubers on the growth and development of phytopathogenic microorganisms

We studied the effect of two proteins, PSPI-21 and PKSI, on the growth and development of phytopathogenic microorganisms (Phytophthora infestans oomycete and Fusarium culmorum fungus). Both proteins were isolated from potato tubers (Solanum tuberosum L., cv. Istrinskii) and served as inhibitors of serine proteinases. These proteins differed in the ability to inhibit growth of Phytophthora infestans oomycete and Fusarium culmorum fungus. PSPI-21 was the most potent in modulating the growth of oomycete mycelium. PKSI primarily affected the growth of the fungal mycelium. The proteins under study induced complete destruction of oomycete zoospores and partial destruction of fungal macroconidia. Our results suggest that these proteins are involved in the protection of potato plants from phytopathogenic microorganisms.     

Effect of proteinaceous proteinase inhibitors from potato tubers on the growth and development of phytopathogenic microorganisms

We studied the effect of two proteins, PSPI-21 and PKSI, on the growth and development of phytopathogenic microorganisms (Phytophthora infestans oomycete and Fusarium culmorum fungus). Both proteins were isolated from potato tubers (Solanum tuberosum L., cv. Istrinskii) and served as inhibitors of serine proteinases. These proteins differed in the ability to inhibit growth of Phytophthora infestans oomycete and Fusarium culmorum fungus. PSPI-21 was the most potent in modulating the growth of oomycete mycelium. PKSI primarily affected the growth of the fungal mycelium. The proteins under study induced complete destruction of oomycete zoospores and partial destruction of fungal macroconidia. Our results suggest that these proteins are involved in the protection of potato plants from phytopathogenic microorganisms.     

Capturing candidate drought tolerance traits in two native Andean potato clones by transcription profiling of field grown plants under water stress.

Candidate traits for drought tolerance were targeted by analyzing water stress responses in two moderately drought-tolerant native Andean potato clones, SA2563 and Sullu (Solanum tuberosum L. subsp, andigena (Juz, Bukasov) Hawkes) under field conditions. SA2563 exhibited increased root growth under drought, while Sullu retained a higher relative leaf water content. Gene expression profiling using the TIGR 10 K microarray revealed 1713 significantly differentially expressed genes, 186 of these genes were up-regulated in both clones. In addition to these commonly up-regulated genes, each clone induced a specific gene set in response to drought. Gene expression and metabolite analysis pinpointed candidate traits for drought tolerance present either in one or both of the clones under investigation. These traits included osmotic adjustment, changes in carbohydrate metabolism, membrane modifications, strengthening of cuticle and cell rescue mechanisms, such as detoxification of oxygen radicals and protein stabilization. Many of the up-regulated genes have been identified previously in laboratory studies on model plants using shock treatments, and the present study confirms the importance of these factors under field conditions.     

Tuber induction and initiation during production and early field growth of transplants from in vitro-derived potato plants

In transplants from in vitro‐derived plantlets from very early potato (Solanum tuberosum) cultivars, a lower degree of tuber induction at the time of field planting is thought to increase tuber production. Leaf‐bud cuttings were used to assess the progress to tuber induction in in vitro‐derived potato plantlets during the transplant production phase and after subsequent transplanting into the field. Induction and initiation of tubers on the same plants were assessed to study the effects of the duration of transplant production and conditions during transplant production for cv. Gloria (very early) and cv. Bintje (mid‐early). In vitro‐produced plantlets were not induced by the time of planting but rapidly progressed to the induced state thereafter. The progress in induction with time and the change in percentage of plants showing tubers fitted typical sigmoid curves. Plantlets achieved 50% induction ca 15 days after planting into in vivo conditions, and 50% tuber initiation usually occurred 10 days later. Shorter transplant production periods reduced the degree of induction of the transplants at field planting. Transplant production for more than 2 weeks was required to allow conditions during that period to affect induction or initiation. Long‐term non‐inducing conditions delayed the progress to tuber induction in cv. Gloria and delayed tuber initiation in both cultivars. Cv. Gloria showed no faster progress to induction than cv. Bintje but initiated tubers earlier. The results suggest that the relation between progress to induction and tuber initiation is cultivar dependent and that leaf‐bud cuttings can be used successfully in very young in vitro‐derived plants for assessing the progress to tuber induction.     

Enhancement of metabolizing herbicides in young tubers of transgenic potato plants with the rat CYP1A1 gene

A rat P450 monooxygenase gene (CYP1A1) was introduced into potato plants to enhance the metabolism of the environmental contaminants in subterranean organs. The CYP1A1 gene was kept under the control of the potato patatin promoter to enhance tuber-specific expression. A total of 106 transgenic plants (PAT1A1 plants) were obtained following selection by a resistance test to kanamycin and PCR analysis. PAT1A1 plants treated with 10% exogenous sucrose showed a higher activity of monooxgenase in the leaves than the non-transgenic plants. This indicated that the activity enhanced by 10% sucrose was due to the patatin promoter containing the sucrose-inducted elements. One representative transgenic plant, Ag2197, was selected on the basis of monooxgenase activity in the leaves and Western blot analysis. Ag2197 was found to accumulate a large amount of CYP1A1 mRNA and protein in the developing tuber but not in the mature tuber. The residual herbicides, atrazine and chlortoluron, were analyzed in the micro-tubers of Ag2197 and non-transgenic plants. The amount of residual herbicides in Ag2197 was much lower than that in the non-transgenic plant, indicating that the transgenic plant metabolized the herbicides to a detoxified form. The transgenic plants produced in this study might be useful for the phytoremediation of chemical pollution in the soil.     

草菇MADS-box转录因子Vvrin1基因过表达转化子菌株的构建及其生长速度的初步差异分析

新鲜草菇味道鲜美,香味浓郁,而且营养丰富,是具有中国特色的食药用菌。草菇采后极易开伞,低温贮藏（10℃以下）则容易自溶、渗水腐、发出异味,是最不易贮藏的食用菌之一。本课题组先前的研究表明草菇MADS-box转录因子Vvrin1基因可能在草菇菌柄的伸长、菌盖的开伞过程中起到一定的作用。因此,本研究以Vvrin1基因为研究对象,构建该基因的过表达载体,通过农杆菌介导的方法进行转化草菇异核菌株H1521菌丝块。通过潮霉素抗性平板筛选,PCR扩增潮霉素抗性基因及Vvrin1基因过表达特异片段,qRT-PCR分析拟转化子菌株内的Vvrin1基因表达量,最终获得了8个比较可靠的转化子。进一步对这些转化子的表型进行初探,发现其中7个转化子的生长速度比出发菌株H1521快,具有显著性差异（P<0.05）,且转化子菌丝更浓密,菌落表面颜色更深,推测草菇MADS-box转录因子Vvrin1基因可能参与了菌丝阶段生长速度和色素合成或积累的调控。研究结果为进一步研究草菇MADS-box转录因子Vvrin1基因的功能提供了菌株材料及数据支持。     

Influences of vermicomposts on field strawberries: 1. effects on growth and yields

Vermicomposts processed commercially from food wastes and paper wastes were applied, to 4.5 m(2) field plots, under high plastic hoop tunnels, at rates of 5 or 10 tha(-1) to evaluate their effects on the growth and yields of strawberries (Fragaria ananasa) var. 'Chandler'. The vermicomposts were incorporated into the top 10 cm of soil and supplemented, based on chemical analyses, with amounts of inorganic NPK fertilizers calculated to equalize the initial fertilizer rates of 85-155-125 kgha(-1) NPK applied to the inorganic fertilizer plots. All treatments were replicated four times, in a completely randomized design, at two field sites on Doles silt loam or Hoytville silty clay loam at Piketon and Fremont, Ohio, respectively. Vermicompost applications increased strawberry growth and yields significantly; including increases of up to 37% in leaf areas, 37% in plant shoot biomass, 40% in numbers of flowers, 36% in numbers of plant runners and 35% in marketable fruit weights. These responses seemed not to be dose-dependent, since strawberries at one site grew fastest and yielded most in response to the 10 tha(-1) vermicompost application rate, whereas they responded positively and similarly to both the 5 and 10 tha(-1) rates of applications at the other site. These responses could not have been mediated by availability of macronutrients, since all plots were supplemented with inorganic fertilizers, to equalize macronutrient inputs for all treatments, but based on other research in our laboratory could have been due to production of plant growth regulators by microorganisms during vermicomposting.