Zinc‐deficiency resistance and biofortification in plants

Zinc (Zn) deficiency is a well‐documented problem in plants, causing decreased yields and nutritional quality. When facing a shortage in Zn supply, plants acclimatize by enhancing the Zn acquisition. In this review, we highlight recent progress in understanding of plant resistance to Zn deficiency and discuss the future challenges to fully unravel its molecular basis of regulation. Emphasis is given on the physiological and molecular basis of Zn acquisition, the long‐distance transport of Zn and the genotypic variations in Zn use efficiency of plants. Prospects of Zn biofortification strategies as well as further efforts for crop improvement to overcome Zn deficiency are also addressed.     

Engraftment of canine peripheral blood lymphocytes into nonobese diabetic-severe combined immune deficient IL-2R common gamma chain null mice

To study the canine immune system we generated a mouse model engrafted with canine lymphocytes using NOD SCID IL2R common gamma chain ?/? (NSG) mice as recipients (Ca-PBL-SCID). Engraftment of canine peripheral blood lymphocytes (PBLs) was determined post-injection with 10⁷ peripheral blood mononuclear cells (PBMCs) into irradiated NSG mice using flow cytometry and fluorescently labeled antibodies specific to canine helper T cells (CD45⁺ CD4⁺), cytotoxic lymphocytes (CD45⁺ CD8⁺), regulatory T cells (CD45⁺ CD4⁺ Foxp3⁺), and B cells (CD45⁺ Ig⁺ CD21_lo). Canine CD45⁺ lymphocytes were detectable as early as day 1 in the peritoneal cavity, and beginning at 9 days in the blood, bone marrow, and spleen. CD4⁺ T cells, of which Foxp-3⁺ CD25_hi cells constituted a minor percentage, were the predominant lymphocyte population at 9 days post engraftment contrasting with increasing proportions of CD8⁺ CTL's and Ig⁺ B cells beginning at 16 days. Canine immunoglobulin was initially detected in the serum of Ca-PBL-SCID mice at 9 days post-engraftment and peaked in concentration at day 36. From day 28 to 52 post-engraftment 30% of the Ca-PBL-SCID mice became markedly anemic and thrombocytopenic, yet gross and histopathologic examination of bone marrow, kidneys, spleen, liver, and intestine revealed no obvious lesions. Blood smear evaluation revealed agglutination of mature red blood cells, reticulocytes and a regenerative anemia. These findings demonstrate that NSG mice are capable of engraftment of canine PBLs yet develop graft versus host disease similar to Hu-PBL-SCID mice.     

Subsoil rhizosphere modification by chickpea under a dry topsoil: implications for phosphorus acquisition

Chickpea (Cicer arietinum L.) roots exude carboxylates. While chickpea commonly grows where the topsoil dries out during crop growth, the importance of carboxylate exudation by the roots and mobilization of soil P from below the dry topsoil has not been examined. The study investigates the response of carboxylate exudation and soil P mobilization by this crop to subsoil P fertilizer rate. In constructed soil columns in the glasshouse, the P levels (high, low, and nil P) were varied in the well‐watered subsoil (10–30 cm), while a low level of P in the dry topsoil (0–10 cm) was maintained. At flowering, rhizosphere carboxylates and rhizosphere soil from topsoil and subsoil roots were collected separately and analyzed. The concentration of total carboxylates per unit rhizosphere mass in the subsoil was nearly double that of the topsoil. Plants depleted sparingly soluble inorganic P (P_i), NaOH‐P_i, and HCl‐P_i, along with the labile P_i (water soluble and NaHCO₃‐Pi). The P depletion by plants was greater from the subsoil than the topsoil. The study concluded that depletion of sparingly soluble P from the chickpea rhizosphere in the subsoil was linked with the greater levels of carboxylates in the rhizosphere. These findings indicate that chickpea, with its deep rooting pattern, can increase its access to subsoil P when the topsoil dries out during crop growth by subsoil rhizosphere modification.     

Salinity Preference of Two Diatoms and Their Growth Performance in Three Prepared and Two Alternative On-Farm Media Sources

ABSTRACT

Salinity and preferred nutrient composition of Chaetoceros affinis and Skeletonema costatum were tested. Salinity was tested at 12, 16, 23, 28, and 32 ppt. Three compositions of nitrogen (N), phosphorus (P), and potassium (K) and two on-farm low-cost alternative media sources, cow urine (CU) and hatchery waste water (HWW), were tested to find the suitable NPK ratio and to determine the efficacy of the on-farm media respectively. Chaetoceros affinis preferred 23 ppt salinity, while Skeletonema costatum preferred both 28 and 32 ppt. Among the NPK treatments, higher cell density was observed in 4:1:1 followed by 4:2:1 ratios. Significant differences in maximum cell density of both species were observed in the NPK treatments while only S. costatum showed significant difference in CU and HWW.     

Seroprevalence of brucellosis and Q fever (Coxiellosis) in cattle herds in Maigana and Birnin Gwari agro-ecological zone of Kaduna State,Nigeria

Tropical Animal Health and Production - A cross sectional study was conducted to determine the seroprevalence and risk factors of brucellosis and Q fever in cattle in Maigana and Birnin Gwari...     

Biochemical impacts of salinity on the catfish,Heteropneustes fossilis (Bloch, 1794), and possibility of their farming at low saline water

Although a stenohaline freshwater fish, the stinging catfish Heteropneustes fossilis, is also available in the freshwater fringes of the coastal areas of Bangladesh, the tolerance of this species to variable environmental salinity has not been thoroughly investigated. Based on median lethal salinity (MLS‐50 96 h), three sublethal salinity levels (3 ppt, 6 ppt and 9 ppt) and a control (0 ppt), each with three replications were selected to observe the effects of mildly brackish conditions on the fish for a period of 90‐day exposure. Better growth and survival were found up to 6 ppt compared with control. Salinity more than 6 ppt appeared unsuitable for H. fossilis fingerling due to increased mortality and reduced growth. To determine biochemical alterations, a few important physiological parameters were observed after 90 days of exposure. Glycogen level of liver and muscle in the fish reared at 9 ppt salinity decreased significantly (P < 0.05) as compared to the control. Glucose level in blood and liver was also found to be increased in fish with increase in salinity. ALP and ATPase activities were reduced significantly in both muscle and liver tissues at higher salinity, indicating the stress mitigation effect. However, all the biochemical parameters were found in normal condition up to 6 ppt compared with control. This evidence suggests that H. fossilis can sustain and grow well below 6 ppt and can be a potential candidate for culture in coastal areas after heavy downpour when the salinities level falls to 6 ppt or lower.     

Effect of chelating agent in disperse dye dyeing on polyester fabric

In this study, mild acid based chelating agents (glycolic acid, gluconic acid, ethylenediaminetetraacetic acid, and citric acid) were used for the dyeing of polyester fabrics with metal sensitive disperse dye in closed dyeing process. The chelating and pH adjustment efficiencies were compared in disperse dyeing condition. In the comparative analysis with different chelating agents, glycolic acid showed a higher chelation efficiency and consequently showed higher dye bath exhaustion and color strength. Slight differences in the color fastness of the dyed samples obtained by employing four different chelating agents were observed.     

Evaluation of elite bread wheat lines for resistance to blast disease in Bangladesh

Euphytica - Genetic approaches often lead to the most cost-effective and efficient means to improve crops, especially those grown widely. But for most crops, cotton included, genetic improvement...     

Effect of long-term chemical and organic fertilization on rice productivity,nutrient use-efficiency,and balance under a rice-fallow-rice system

Nutrient sources and management influence soil properties and crop productivity indicating that sustained crop production needs nutrient rate specific tuning after certain periods of time. We hypothesize that long-term use of organic and inorganic nutrient sources maintains soil fertility and improve crop production. Yield and nutrient use efficiencies have not been evaluated in Bangladesh from long-term fertilizer trials focusing on adaptation strategies for sustained food production. So, the objectives of the present investigation were to examine the effects of organic and inorganic amendments on yields and soil properties under a rice-fallow-rice system. The experiment was initiated in 1985 with 12 treatments under dry season irrigated rice culture at the Bangladesh Rice Research Institute, Gazipur. The effects of organic and inorganic nutrient sources were evaluated under missing element techniques. The contributions of nitrogen (N), phosphorus (P), and potassium (K) fertilizers to yields were more in the dry season but the role of P was negligible in the wet season. The omissions of N, P and K nutrients are not suitable management option for rice cultivation during dry and wet seasons, although P can be omitted in the wet season provided its full dose is applied in the dry season. The combined use of organic and inorganic nutrient sources are the best option for improving rice productivity and sustaining soil fertility in a rice-fallow-rice system in Bangladesh.