Response of mannitol-producing Arabidopsis thaliana to abiotic stress

2007 ◽  
Vol 34 (4) ◽  
pp. 382 ◽  
Author(s):  
Christine M. Sickler ◽  
Gerald E. Edwards ◽  
Olavi Kiirats ◽  
Zhifang Gao ◽  
Wayne Loescher

In celery, mannitol is a primary photosynthetic product that is associated with celery’s exceptional salt tolerance. Arabidopsis plants transformed with celery’s mannose-6-phosphate reductase (M6PR) gene produce mannitol and grow normally in the absence of stress. Daily analysis of the increase in growth (fresh and dry weight, leaf number, leaf area per plant and specific leaf weight) over a 12-day period showed less effect of salt (100 mm NaCl) on the M2 transformant than wild type (WT). Following a 12-day treatment of WT, M2 and M5 plants with 100 or 200 mm NaCl the total shoot fresh weight, leaf number, and leaf area were significantly greater in transformants than in WT plants. The efficiency of use of energy for photochemistry by PSII was measured daily under growth conditions. In WT plants treated with 100 mm NaCl, the PSII yield begin decreasing after 6 days with a 50% loss in yield after 12 days, indicating a severe loss in PSII efficiency; whereas, there was no effect on the transformants. Under atmospheric levels of CO2, growth with 200 mm NaCl caused an increase in the substomatal levels of CO2 in WT plants but not in transformants. It also caused a marked decrease in carboxylation efficiency under limiting levels of CO2 in WT compared with transformants. When stress was imposed and growth reduced by withholding water for 12 days, which resulted in a similar decrease in relative water content to salt-treated plants, there were no differences among the genotypes in PSII yields or growth. The results suggest mannitol, which is known to be a compatible solute and antioxidant, protects photosynthesis against salt-related damage to chloroplasts.

2021 ◽  
Vol 30 (2) ◽  
pp. 159-168
Author(s):  
Shabnur Chowdhury ◽  
MK Rahman

Effects of organic manures on growth and yield of lettuce (Lactuca sativa L.) and nutrient accumulation in its leaves was examined. The experiment was conducted in a completely randomized design (CRD) replicated thrice with ten treatments involving nine organic manures and a control treatment. Growth parameters viz. plant height, leaf number, leaf length, leaf area, leaf area index and fresh and dry weight of leaf, stem and root were assessed. The highest height (23.69 cm), longest leaf (32.18cm), leaf area (5883.43cm2), leaf area index (6.434), fresh weight (85.41 g) and dry weight (42.73 g) were found in Payel organic manure. The maximum leaf number (27) was recorded in Approshika organic manure. The maximum content of nitrogen (6.12%), phosphorus (1.83%), potassium (4.11%) and Sulphur (1.69%) were observed in Payel organic manure. The best growth performance and nutrient accumulation was observed in Payel organic manure. Dhaka Univ. J. Biol. Sci. 30(2): 159-168, 2021 (July)


2008 ◽  
Vol 74 (21) ◽  
pp. 6584-6590 ◽  
Author(s):  
Boguslaw Lupa ◽  
Erik L. Hendrickson ◽  
John A. Leigh ◽  
William B. Whitman

ABSTRACT Methanococcus maripaludis, an H2- and formate-utilizing methanogen, produced H2 at high rates from formate. The rates and kinetics of H2 production depended upon the growth conditions, and H2 availability during growth was a major factor. Specific activities of resting cells grown with formate or H2 were 0.4 to 1.4 U�mg−1 (dry weight). H2 production in formate-grown cells followed Michaelis-Menten kinetics, and the concentration of formate required for half-maximal activity (Kf ) was 3.6 mM. In contrast, in H2-grown cells this process followed sigmoidal kinetics, and the Kf was 9 mM. A key enzyme for formate-dependent H2 production was formate dehydrogenase, Fdh. H2 production and growth were severely reduced in a mutant containing a deletion of the gene encoding the Fdh1 isozyme, indicating that it was the primary Fdh. In contrast, a mutant containing a deletion of the gene encoding the Fdh2 isozyme possessed near-wild-type activities, indicating that this isozyme did not play a major role. H2 production by a mutant containing a deletion of the coenzyme F420-reducing hydrogenase Fru was also severely reduced, suggesting that the major pathway of H2 production comprised Fdh1 and Fru. Because a Δfru-Δfrc mutant retained 10% of the wild-type activity, an additional pathway is present. Mutants possessing deletions of the gene encoding the F420-dependent methylene-H4MTP dehydrogenase (Mtd) or the H2-forming methylene-H4MTP dehydrogenase (Hmd) also possessed reduced activity, which suggested that this second pathway was comprised of Fdh1-Mtd-Hmd. In contrast to H2 production, the cellular rates of methanogenesis were unaffected in these mutants, which suggested that the observed H2 production was not a direct intermediate of methanogenesis. In conclusion, high rates of formate-dependent H2 production demonstrated the potential of M. maripaludis for the microbial production of H2 from formate.


HortScience ◽  
1990 ◽  
Vol 25 (12) ◽  
pp. 1578-1581 ◽  
Author(s):  
Curt R. Rom ◽  
Bruce Barritt

The role of spur leaves in bud and fruit development on two spur-type `Delicious' apple strains (Malus domestica Borkh.) and factors affecting spur development were studied. Reducing spur leaf area on vegetative spurs in August reduced the number of spurs that flowered the following year but did not affect flower size. On spurs that did flower, leaf area reduction the previous year did not influence leaf number or area, but the bourse shoot leaf area was reduced. Spur bud diameter, leaf area, size, specific leaf weight (SLW), and leaf dry weight were larger on 2-year-old vegetative spurs than on 1- or 3-year-old spurs. Within each age section of a limb, spur leaf number, area, size, SLW, and bud diameter decreased from the apical to basal positions on the limb. Flower number did not vary within a limb section, but fruit set was lower on the most apical and basal spurs compared to midshoot spurs. Fruit size was largest at the apical end of each limb section and was smallest at basal positions. These relationships were not affected by strain, tree age, or orchard location. Summer pruning at 30 days after bloom tended to increase leaf number, area, size, and spur length compared to unpruned trees or pruning later in the season but did not influence spur bud diameter.


2018 ◽  
Vol 20 (1) ◽  
pp. 1
Author(s):  
Daru Nurdianna ◽  
Retno Bandriyati Arni Putri ◽  
Dwi Harjoko

This study aims to determine the differences in the growth response of green curly lettuce to the differentiation treatment of LED lighting with different spectrum in indoor hydroponics. The research was conducted from October to November 2017. The experimental design used was experimental with 1 lighting factor with 5 levels, there are sunlight (P0), LED 20% blue: 80% red (P1), LED 80% blue: 20% red (P2), 50% blue LED: 50 % red (P3), and 100% white daylight (P4). Observational variables included plant height, leaf number, leaf area, leaf color, total wet weight, leaf wet weight, wet root weight and dry weight of the plant. The result of this experiment showed that LED irradiation have affect the treatment are plant height, leaf number, leaf area, chlorophyll content, fresh weight of harvest, root length, and dry weight of brackets. While those that have no significant effect are the wet weight of the roots. The results showed that between LED irradiation treatment L1, L2, L3, and L4 showed that treatment L2 with 80% blue spectrum composition: 20% red showed better growth based on: high plant, chlorophyll content, and root length. Treatment with L4 with white LED showed better growth based on the number of leaves, leaf area, fresh weight of harvest, root wet weight, and dry weight of total biomass. The results below the sunlight better than the LED irradiation treatment, because the intensity of LED far low and lack of controlled environmental conditions technology and management for growing lettuce. In all of LED treatment still looked etiolation because light intensity was not optimal yet.


HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 771-774 ◽  
Author(s):  
Youbin Zheng ◽  
Linping Wang ◽  
Diane Feliciano Cayanan ◽  
Mike Dixon

To determine the nutrient solution copper (Cu2+) level above which Cucumis sativus L. (cucumber, cv. LOGICA F1) plant growth and fruit yield will be negatively affected, plants were grown on rockwool and irrigated with nutrient solutions containing Cu2+ at 0.05, 0.55, 1.05, 1.55, and 2.05 mg·L−1. Copper treatment began when plants were 4 weeks old and lasted for 10 weeks. During this 10-week period, plants were harvested at 3 weeks (short-term) and 10 weeks (long-term) after the start of Cu2+ treatment. Neither visible leaf injury nor negative Cu2+ effect was observed on plant growth (leaf number, leaf area, leaf dry weight, and stem dry weight) after 3 weeks of continuous Cu2+ treatment. However, after 10 weeks of continuous Cu2+ application, cucumber leaf dry weight was significantly reduced by Cu2+ levels 1.05 mg·L−1 or greater; leaf number, leaf area, and stem dry weight were significantly reduced by Cu2+ levels 1.55 mg·L−1 or greater. Copper (Cu2+ levels 1.05 mg·L−1 or greater) also caused root browning. Some plants under the 2.05 mg·L−1 Cu2+ treatment started to wilt after 6 weeks of continuous Cu2+ treatment. Copper treatment did not result in any change in leaf greenness until after Week 9 from the start of the treatments. There was no sign of a negative Cu2+ effect on cucumber fruit numbers after the first 2 weeks of production, but plants under the highest Cu2+ concentration treatment (2.05 mg·L−1) gradually produced fewer cucumber fruit than the control (0.05 mg·L−1) and eventually resulted in lower cucumber yield. Nutrient solution can be treated with 1.05 mg·L−1 of Cu2+ in cucumber production greenhouses; however, it is not recommended to use Cu2+ concentrations 1.05 mg·L−1 or greater continuously long-term (more than 3 weeks). When applying Cu2+, it is suggested that cucumber roots be examined regularly because roots are a better indicator for Cu2+ toxicity than leaf injury.


1970 ◽  
Vol 5 (1) ◽  
Author(s):  
Lia Karlina Br Sembiring ◽  
Rosita Sipayung ◽  
Irsal

Massive breeding is often the case with the availability of the amount of water that can be stored on the media. The aim of this research is to know the influence of media and the frequency of watering on the growth of robusta coffee seedlings and to find the best media and optimum watering frequency. This experiment was conducted at the Faculty of Agriculture, University of Sumatera Utara, Medan from June to September 2017. The experimental method used was Factorial Randomized Block Design with 2 treatment factors, ie 1: planting medium ie, topsoil ; topsoil: sand (2: 1); topsoil: rice husk (2: 1), topsoil: charcoal husk (2: 1) and factor 2: watering frequency ie, watered once a day; watered every 4 days; watered 7 days and watered once every 10 days. The variable was plant height, stem diameter, total leaf number, total leaf area, fresh crown weight, canopy dry weight, fresh root weight, root dry weight, longest root, and canopy and root ratio. The results showed that planting media treatment had a significant effect on plant height variables, stem diameter increase, leaf number, total leaf area, fresh crown weight, canopy dry weight, fresh root weight, root dry weight, and root canopy ratio. The best treatment of planting medium was found in topsoil treatment: rice husk (2: 1). The treatment of watering frequency had a significant effect on the stem diameter 2 - 12 of the week after planting move observation variable, total leaf area, fresh crown weight, dry crown weight, fresh root weight, and dry weight of roots. The best treatment frequency of watering hose is watering every 4 days. The interaction between the two treatments had a significant effect on the diameter of the stem diameter variable, the total leaf area and the fresh weight of the canopy.


1983 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
DW Turner ◽  
E Lahav

Bananas (cv. Williams) were grown for 12 weeks in sunlit growth chambers at day/night temperatures of 17/10, 21/14, 25/18, 29/22, 33/26 or 37/30°C. Humidity was not controlled. At 17/10°C, the plants showed chilling injury and heat injury occurred at 37/30°C. Total plant dry weight was greatest at 25/18°C while leaf area was greatest at 33/26°C. At high temperatures proportionately less dry matter was present in the roots and corm compared with plants at 25/18°C. High temperatures produced more horizontal leaves but, to compensate for this, the laminae folded more readily. Lamina folding was closely associated with relative water content of the laminae, except under cool conditions where laminae folded despite high (97-99%) leaf relative water contents. Unit leaf rate (increase in whole plant dry weight per unit leaf area per unit time) was greatest at 21/14°C (5.8 g m-2 day-1) and least at 37/30°C (1.7 g m-2 day-1.) and had a strong negative association with whole-plant leaf resistance. Leaf relative water content was more closely associated with vapour pressure deficit than temperature and even at 37/30°C was high at 94%.


Pastura ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 105
Author(s):  
Roni N. G. K. ◽  
S. A. Lindawati

This study aims to obtain a study of the productivity of Gliricidia sepium and Indigofera zollingeriana plants which are given various dosage of bioorganic fertilizer. This study used a completely randomized design of factorial patterns of two factors: the first factor was the type of plant (G = Gamal; I = Indigofera) and the second factor was the dosage of bioorganic fertilizer: D0 = without fertilizer; D1 = 5 tons ha-1; D2 = 10 tons ha-1; D3 = 15 tons ha-1; D4 = 20 tons ha-1; D5 = 25 tons ha-1; and D6 = 30 tons ha-1, so there are 14 treatment combinations. Each treatment was repeated three times so that it consisted of 42 experimental units. The variables observed were plant height, leaf number, stem diameter, leaf dry weight, stem dry weight, total herbage dry weight, amount of chlorophyll, ratio of dry weight of leaf / stems, and leaf area per pot. The results showed that the productivity of Indigofera zollingeriana significant higher than Gliricidia sepium. The application of bioorganic fertilizer significantly increased plant height, leaf number, dry weight leaf, stem dry weight, total forage dry weight, amount of chlorophyll, and leaf area per pot, and the highest yield at 30 tons/ha. Based on the results of the study it can be concluded that the productivity of Indigofera zollingeriana is higher than Gliricidia sepium, bioorganic fertilizer increased plant productivity with the highest yield at 30 tons ha-1, and interaction only occurs in the leaf area per pot. Keywords: Indigofera zollingeriana, Gliricidia sepium, dosage of fertilizer, bioorganic fertilizer


Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2201
Author(s):  
Sally A. Arafa ◽  
Kotb A. Attia ◽  
Gniewko Niedbała ◽  
Magdalena Piekutowska ◽  
Salman Alamery ◽  
...  

In the present investigation, we study the effect of Bacillus thuringiensis MH161336 (106–8 CFU/cm3), silicon (25 mL L−1), and carrot extract (75 mL L−1) as seed primers, individually or in combination, on morphological, physio-biochemical and yield components of drought-stressed pea plants (Master B) during 2019/2020 and 2020/2021 seasons. Our results indicated that drought causes a remarkable reduction in plant height, leaf area, number of leaves per plant, and number of flowers per plant in stressed pea plants during two seasons. Likewise, number of pods, pod length, seeds weight of 10 dried plants, and dry weight of 100 seeds were decreased significantly in drought-stressed pea plants. Nevertheless, seed priming with the individual treatments or in combination boosted the morphological, physio-biochemical, and yield characters of pea plants. The best results were obtained with the Bacillus thuringiensis + carrot extract treatment, which led to a remarkable increase in the number of leaves per plant, leaf area, plant height, and number of flowers per plant in stressed pea plants in both seasons. Moreover, pod length, number of seeds per pod, seeds weight of 10 dried plants, and dry weight of 100 seeds were significantly increased as well. Bacillus thuringiensis + carrot extract treatment led to improved biochemical and physiological characters, such as relative water content, chlorophyll a, chlorophyll b, regulated the up-regulation of antioxidant enzymes, increased seed yield, and decreased lipid peroxidation and reactive oxygen species, mainly superoxide and hydrogen peroxide, in drought-stressed pea plants.


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