Alleviation Effect of Lanthanum on Cadmium Stress in Seedling Hydroponic Culture of Kidney Bean and Corn

The seedling hydroponic culture experiment of kidney bean （ Phaseolus vulgaris ） and corn （ Zea mays ） was conducted to investigate the alleviation effect of lanthanum on Cd stress. It is found that growth is seriously inhibited and metabolism is maladjusted in the two crops under 30 and 300 μmol·L^-1 Cd^2＋ stress. Plant height, taproot length, leaf area, and fresh or dry weight of root, stem, and leaf are all obviously decreased. Further, chlorophyll content decreases, membrane permeability, malonydialdehyde （MDA） content, activities of catalase （CAT） and peroxidase （POD） increases under Cd stress, as compared with the control. The damage to these two crops becomes more conspicuous with the prolongation of Cd stress. It is suggested that lanthanum might help kidney bean and corn seedlings alleviate Cd stress by improving the photosynthetic capacity, reducing membrane permeability and MDA content, and maintaining the activities of CAT and POD of these two crops.

Tolerance of Four Market Classes of Dry Beans to Tribenuron and Carfentrazone Applied Preplant

Limited information is available on the sensitivity of dry beans to tribenuron and carfentrazone applied preplant (PP). Four field trials were conducted at Exeter and Ridgetown, ON, Canada in 2019 and 2020 to determine the tolerance of azuki, kidney, small red and white beans to glyphosate (1800 g·ae·ha-1) + tribenuron (15 g·ai·ha-1), glyphosate (1800 g·ae·ha-1) + carfentrazone (35 g·ai·ha-1) and glyphosate (1800 g·ae·ha-1) + tribenuron (15 g·ai·ha-1) + carfentrazone (35 g·ai·ha-1) applied PP 1 - 2 days prior to seeding dry beans. Glyphosate + tribenuron, glyphosate + carfentrazone, and glyphosate + tribenuron + carfentrazone, applied PP, caused 5%, 5% and 9% bean injury at 1 WAE;7%, 6% and 10% bean injury at 2 WAE and 6%, 5% and 8% bean injury at 4 WAE, respectively. At 8 WAE, there was 0, 1% and 4% injury in azuki bean;1%, 2% and 2% injury in kidney bean;3%, 2% and 3% injury in small red bean;and 6%, 3% and 2% injury in white bean with glyphosate + tribenuron, glyphosate + carfentrazone, and glyphosate + tribenuron + carfentrazone applied PP, respectively. The injury was significantly greater with glyphosate + tribenuron in small red and white beans compared to the azuki and kidney beans. There was no difference between injury levels among market classes of dry been with glyphosate + carfentrazone or glyphosate + tribenuron + carfentrazone applied PP. There was no effect of glyphosate + tribenuron, glyphosate + carfentrazone and glyphosate + tribenuron + carfentrazone on dry bean plant stand, maturity and seed yield. However, dry bean biomass was reduced as much as 15% with glyphosate + tribenuron and 13% with glyphosate + tribenuron + carfentrazone compared to the untreated control. Dry bean height was reduced 4% with glyphosate + tribenuron + carfentrazone but was not affected with other treatments. Based on these results, there is potential for using glyphosate plus tribenuron or carfentrazone for preplant weed management in dry bean production.

Evaluation of Physicochemical Properties and Antioxidant Activity of Wheat-Red Kidney Bean Biscuits

This research was aimed to study the physicochemical properties and antioxidant activity of biscuits fortified with red kidney bean (Phaseolus vulgaris) powder. Proximate compositions, total phenol content, antioxidant activity, and functional properties of red kidney bean (RKB) powder were studied before and after the incorporation of red kidney bean in the biscuits. The bean powder was mixed with wheat flour at a level of 0% as control, 10%, 20%, and 30% during dough preparation. Results revealed that RKB powder is a rich source of protein (26.25%) together with carbohydrate (59.7%), fat (2.4%), and ash (3.27%). The total phenolic content of bean powder was 14.15 mg GAE/g. Kidney bean powder showed good functional properties including water absorption capacity (149.7%), oil holding capacity (99.54%), swelling capacity (4.6%), and bulk density of 0.74 g/ml. After increasing the percentage of RKB with control, there were significant increases (p < 0.05) in the levels of protein, moisture, ash, fat, while carbohydrate content and total gross energy decreased significantly. Investigation of total phenolic content showed the increasing trend with the higher RKB fortification, which amounted to 10.31 mg GAE/g for control and 12.50 mg GAE/g for 30% RKB. DPPH radical scavenging activity was investigated for all the samples at five different concentrations. As there was an increase in the percentage of RKB and concentration of the samples, the antioxidant activity also increased significantly (p < 0.05), where IC50 value decreased from 0.0228 mg/ml for control to 0.0289 mg/ml for 10% RKB, followed by 20% and 30% RKB, respectively. In sensory test, the control cake secured the highest score in color, flavor, texture and overall acceptability followed by the cake incorporated with 10% freeze-dried mushroom powder.

Response of Four Dry Bean Market Classes to Pre-Emergence Applications of Pyroxasulfone, Sulfentrazone and Pyroxasulfone plus Sulfentrazone

Only one herbicide mode of action (ALS inhibitor) is currently available to Ontario dry bean producers for soil-applied broadleaf weed control. Four field studies were conducted over two years (2014, 2015) to examine the tolerance of four market classes of dry beans to sulfentrazone (210 and 420 g·ai·ha-1) and pyroxasulfone (100 and 200 g·ai·ha-1) applied alone and in combination. The registration of these two herbicides would provide Ontario dry bean producers with two additional modes of action for broadleaf weed control. Pyroxasulfone caused up to 23%, 6%, 7% and 10% injury in adzuki, kidney, small red Mexican and white bean, respectively;sulfentrazone caused up to 51%, 12%, 15% and 44% injury and the combination caused up to 90%, 23%, 29% and 62% injury, respectively. Kidney and small red Mexican bean density, height, seed moisture content and yield were not affected. Pyroxasulfone (200 g·ai·ha-1) + sulfentrazone (420 g·ai·ha-1) reduced adzuki and white bean density, shoot dry weight, height and yield. This study concludes that pyroxasulfone (100 g·ai·ha-1) + sulfentrazone (210 g·ai·ha-1) applied PRE can be safely used to control weeds in Ontario kidney and small red Mexican bean production.

Resistance identification of bivalent fungi-resistant genes transformed soybean to Phytophthora sojae

Soybean is one of the most important sources of edible oil and proteins in the world. However, it suffers from many kinds of fungal diseases which is a major limiting factor in soybean production. The fungal disease can be effectively controlled by breeding plant cultivars with genetic transformation. In this study, the resistance to Phytophthora sojae of five bivalent transgenic soybean lines was identified using the hypocotyls inoculation technique. The lines were the T2 of the transgenic soybean which were transformed with kidney bean chitinase gene and barley ribosome inactivating protein gene, and were positive by Southern Blot analysis. The resistance difference was studied through comparing the death percentage of transgenic soybean with the control. The results showed that four lines were more resistant to P sojae, whereas other one had no significant difference in comparison with the control. These transgenic soybean lines with enhanced resistance to P sojae will be useful in soybean resistance breeding.

Comparison of Different MARs(Matrix Attachment Regions) Effect on Transgene Expression

Three MARs(matrix attachment regions)fragments were cloned from tobacco(Nicotiana tabacum)(MAR1), yeast(Saccharomyces cerevisiae)(MAR3)and kidney bean(Phaseolus vulgaris)(MAR5)which ranged 984, 822 and 782bp, respectively. Sequence analysis showed that all thefragments had fairly high A/T content (73, 62 and 75%, respectively),harbored differentnumber and different type of some characteristic motifs of MARs, such as A-box and T-box,etc. The results of in vitro binding assay showed that the three MARs fragments derivedfrom different organisms could bind specifically to the matrix extracted from the tobacconuclei with different strength, which also demonstrated that these MARs fragments arefunctionally conserved during evolution. By using these MARs fragments to flank the β-glucuronidase (GUS) reporter gene and bialaphos resistance(bar) selectable marker gene,and then introducing the resulting plant expression vectors containing MARs-uidA-bar-MARs into tobacco through Agrobacterium mediated procedures, the effects of MARs sequenceson the expression of transgenes in tobacco were investigated and compared. The GUSactivity in individual transformants showed that, comparing to the controls withoutadditional MARs, the overall transgene expression level in transformants with MARs hadbeen greatly increased while the variations in transgene expression among transformantswere decreased in different degrees. In accordance with the results of sequence analysisand in vitro binding assay in which MAR1 fragment showed the strongest binding strength,this MARs fragment also showed the greatest effect in increasing transgene overallexpression level.

Tolerance of Four Dry Bean Market Classes to Pre-Emergence Applications of Sulfentrazone

Ontario dry bean growers are currently limited to ALS inhibitor herbicides for soilapplied broadleaf weed control;therefore another mode of action is needed. Sulfentrazone is a PPO inhibitor herbicide that has activity on some annual grass and broadleaf weed species. Four field trials were conducted over two years (2014, 2015) to determine the tolerance of four commonly grown dry bean market classes (adzuki, kidney, small red Mexican and white bean) to PRE applications of sulfentrazone at 140, 210, 280 and 420 g·ai·ha-1. Crop injury, plant height, plant density, shoot biomass, seed moisture content and yield were examined. Sulfentrazone (420 g·ai·ha-1) caused up to 74%, 22%, 30%, and 57% injury in adzuki, kidney, small red Mexican and white bean, respectively. Plant density, height and yield were not reduced for kidney or small red Mexican bean. Sulfentrazone (420 g·ai·ha-1) reduced white bean plant density, height and yield by 28%, 29% and 29%, respectively;and reduced adzuki bean plant density, height and yield by 51%, 34% and 57%, respectively. Overall, kidney and small red Mexican bean were the most tolerant to sulfentrazone, followed by white bean, and then adzuki. This study determined sulfentrazone applied PRE is safe for Ontario kidney bean and small red Mexican bean crops.

Effects of Enhanced UV-B Radiation on the Activity and Expression of Alternative Oxidase in Red Kidney Bean Leaves

An increase in ultraviolet （UV） B radiation on the earth＇s surface is a feature of current global climate changes. It has been reported that alternative oxidase （AOX） may have a protective role against oxidative stress induced by environmental stresses, such as UV-B. To better understand the characteristic tolerance of plants to UV-B radiation, the effects of enhanced UV-B radiation on the activity and expression of AOX in red kidney bean （Phaseolus vulgaris） leaves were investigated in the present study. The results show that the total respiration rate and AOX activity in red kidney bean leaves increased significantly during treatment with enhanced UV-B. However, cytochrome oxidase （COX） activity did not change significantly. The H2O2 content was also markedly increased and reached a maximum of 4.45 mmol·L^-1·g^-1 DW （dry weight） at 24 h of UV-B treatment, before dropping rapidly. Both alternative pathway content and alternative pathway activity were increased in the presence of exogenous H2O2. Immunoblotting analysis with anti-AOX monoclonal antibody revealed that expression of the AOX protein increased in red kidney bean leaves under enhanced UV-B radiation, reaching a peak at 72 h. In addition, AOX expression in red kidney bean leaves was induced by exogenous H2O2. These data indicate that the increase in AOX activity in red kidney bean leaves under enhanced UV-B radiation was mainly due to H2O2-induced AOX expression.