Physio-biochemical Responses of In Vitro Cooking Banana Musa paradisiaca cv Lang towards Pseudo Induced Drought Stress by Polyethylene Glycol (PEG)

Musa paradisiaca cv Lang belongs to cooking banana group, and it has high potential to be used in banana chips production. Like other cultivars, M. paradisiaca cv Lang is susceptible towards water shortage, therefore affecting banana growth and productivity. In this study, to mimic the drought condition, pseudo-drought stress was given to in vitro Lang banana seedlings by adding polyethylene glycol (PEG). Overall, decrement of roots length and chlorophyll (Chl) content was displayed by the seedlings exposed to 1%, 2%, 3%, 4%, and 5% (w/v) of PEG after three weeks of exposure. The proline content, total soluble protein content, and antioxidant capacity in leaf and roots, however, countered differently towards different levels of drought. Proline content showed the highest in leaf of 2% (w/v) PEG-treated seedling (12.66±0.38 µmoles/g) while the total soluble protein content showed the highest in roots of 5% (w/v) of PEG-treated seedling (30.65±1.07 mg/g FW). Antioxidant capacity of stressed seedlings revealed the catalase (CAT), guaiacol peroxidase (POD), and ascorbate peroxidase (APX) activities were the highest in the leaf of 1% (w/v) (10.69±5.06 µmol/min/mg), 4% (w/v), (0.079±0.03 µmol/min/mg), and 5% (w/v) (9.11±8.47 µmol/min/mg) of PEG- treated seedlings, respectively. Meanwhile, the highest CAT, POD, and APX activities in the roots were determined in 3% (w/v) (0.49±0.04 µmol/min/mg), 2% (w/v) (0.03±0.02 µmol/min/mg), and 3% (w/v) (16.69±0.5 µmol/min/mg) of PEG-treated seedlings, respectively. These data show that PEG can be a priming agent to induce defense system at seedling stage of banana, which could enhance their survivability during ex vitro acclimatization.

OPTIMIZING THE PRODUCTION OF A FUNCTIONAL TYPE A RECOMBINANT ENDOCHITINASE FROM Trichoderma asperellum IN Escherichia coli

Chitinases from the genus Trichoderma fungi are mainly responsible for their anti-fungal activities, which allow them to become the most widely used fungal biocontrol. Therefore, several Trichoderma chitinases have been cloned and expressed to facilitate their production and applications. A previous study of the same authors has characterized an endochitinase from a relatively novel Trichoderma spp., Trichoderma asperellum. To produce this enzyme more economically and efficiently, we reported the synthesis and expression of its synthetic encoding gene in the Escherichia coli M15 strain and established the optimal conditions for preparative scale production of the enzyme in its functional form. By lowering the induction temperatures, we observed substantial improvement in the expression levels of the active enzyme. At 30 oC and 0.5 mM IPTG induction, 1 L of cells yielded approximately 80 - 100 mg of soluble protein, accounting for about 9-11 % of total soluble protein. This figure may be an underestimation of the actual yield, as deduced from the SDS-PAGE data. The recombinant enzyme can be retrieved by simple repeated freezing and thawing cycles and purified to near homogeneity using Ni-NTA chromatography. The purified enzyme showed in vitro colloidal chitin hydrolysis activity. These results could be scaled up to produce soluble 42 kDa chitinase in E. coli. The study demonstrated an economical method to produce chitinases for various agricultural and environmental applications.

Genome-Wide Identification and Expression Profiling of Potassium Transport-Related Genes in Vigna radiata under Abiotic Stresses

Potassium (K+) is one of the most important cations that plays a significant role in plants and constitutes up to 10% of plants’ dry weight. Plants exhibit complex systems of transporters and channels for the distribution of K+ from soil to numerous parts of plants. In this study, we have identified 39 genes encoding putative K+ transport-related genes in Vigna radiata. Chromosomal mapping of these genes indicated an uneven distribution across eight out of 11 chromosomes. Comparative phylogenetic analysis of different plant species, i.e., V. radiata, Glycine max, Cicer arietinum, Oryza sativa, and Arabidopsis thaliana, showed their strong conservation in different plant species. Evolutionary analysis of these genes suggests that gene duplication is a major route of expansion for this family in V. radiata. Comprehensive promoter analysis identified several abiotic stresses related to cis-elements in the promoter regions of these genes, suggesting their role in abiotic stress tolerance. Our additional analyses indicated that abiotic stresses adversely affected the chlorophyll concentration, carotenoids, catalase, total soluble protein concentration, and the activities of superoxide and peroxidase in V. radiata. It also disturbs the ionic balance by decreasing the uptake of K+ content and increasing the uptake of Na+. Expression analysis from high-throughput sequencing data and quantitative real-time PCR experiments revealed that several K+ transport genes were expressed in different tissues (seed, flower, and pod) and in abiotic stress-responsive manners. A highly significant variation of expression was observed for VrHKT (1.1 and 1.2), VrKAT (1 and 2) VrAKT1.1, VrAKT2, VrSKOR, VrKEA5, VrTPK3, and VrKUP/HAK/KT (4, 5, and 8.1) in response to drought, heat or salinity stress. It reflected their potential roles in plant growth, development, or stress adaptations. The present study gives an in-depth understanding of K+ transport system genes in V. radiata and will serve as a basis for a functional analysis of these genes.

Influence of Enzyme Concentration and Hydrolysis Time on Soluble Protein Content of Protein Hydrolysate Prepared from Apple Snail (Pila ampullacea)

The objective of this study was to evaluate soluble protein content of protein hydrolysates obtained by enzymatic hydrolysis of apple snail using a trypsin enzyme. Apple snail were collected from traditional market at Pabean-Sidoarjo. Trypsin enzyme was used in enzymatic hydrolysis. The two variables, enzyme/substrate (E/S) ( 0.01, 0.05, 0.1) ratio and hydrolysis time (3 h, 6 h, 9 h, 12 h, 15 h, 18 h) and was used to produce the apple snail hydrolysate. The result showed that soluble protein content was about 2.3%-4.52%. The increase E/S ratio and hydrolysis time, the higher soluble protein content values was. The highest total soluble protein was achieved E/S 0.1 ratio at 12 h, 4.52%. But, after 12 h hydrolysis time, soluble protein was decreased. Optimum treatment to hydrolyzing apple snail using trypsin enzyme was E3H4 treated (E/S 0.1 ratio and 3 h)

Persulfidation of Nitrate Reductase 2 Is Involved in L-Cysteine Desulfhydrase-Regulated Rice Drought Tolerance

Hydrogen sulfide (H2S) is an important signaling molecule that regulates diverse cellular signaling pathways through persulfidation. Our previous study revealed that H2S is involved in the improvement of rice drought tolerance. However, the corresponding enzymatic sources of H2S and its regulatory mechanism in response to drought stress are not clear. Here, we cloned and characterized a putative L-cysteine desulfhydrase (LCD) gene in rice, which encodes a protein possessing H2S-producing activity and was named OsLCD1. Overexpression of OsLCD1 results in enhanced H2S production, persulfidation of total soluble protein, and confers rice drought tolerance. Further, we found that nitrate reductase (NR) activity was decreased under drought stress, and the inhibition of NR activity was controlled by endogenous H2S production. Persulfidation of NIA2, an NR isoform responsible for the main NR activity, led to a decrease in total NR activity in rice. Furthermore, drought stress-triggered inhibition of NR activity and persulfidation of NIA2 was intensified in the OsLCD1 overexpression line. Phenotypical and molecular analysis revealed that mutation of NIA2 enhanced rice drought tolerance by activating the expression of genes encoding antioxidant enzymes and ABA-responsive genes. Taken together, our results showed the role of OsLCD1 in modulating H2S production and provided insight into H2S-regulated persulfidation of NIA2 in the control of rice drought stress.

Modulation of Cellular Redox Status and Antioxidant Defense System after Synergistic Application of Zinc Oxide Nanoparticles and Salicylic Acid in Rice (Oryza sativa) Plant under Arsenic Stress

The objective of this research was to determine the effect of zinc oxide nanoparticles (ZnONPs) and/or salicylic acid (SA) under arsenic (As) stress on rice (Oryza sativa). ZnONPs are analyzed for various techniques viz., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). All of these tests established that ZnONPs are pure with no internal defects, and can be potentially used in plant applications. Hence, we further investigated for better understanding of the underlying mechanisms and the extent of ZnONPs and SA induced oxidative stress damages. More restricted plant growth, gas exchange indices, significant reduction in the SPAD index and maximum quantum yield (Fv/Fm) and brutal decline in protein content were noticed in As-applied plants. In contrast, foliar fertigation of ZnONPs and/or SA to As-stressed rice plants lessens the oxidative stress, as exposed by subordinate levels of reactive oxygen species (ROS) synthesis. Improved enzymatic activities of catalase (CAT), peroxidase (POX), and superoxide dismutase (SOD), proline and total soluble protein contents under ZnONPs and SA treatment plays an excellent role in the regulation of various transcriptional pathways participated in oxidative stress tolerance. Higher content of nitrogen (N; 13%), phosphorus (P; 10%), potassium (K; 13%), zinc (Zn; 68%), manganese (Mn; 14%), and iron (Fe; 19) in ZnONPs and SA treated plants under As-stress, thus hampered growth and photosynthetic efficiency of rice plants. Our findings suggest that toxicity of As was conquering by the application of ZnONPs and SA in rice plants.

Quinoa Seed Germination and Vigor Index with Bacterization of Pseudomonas aeruginosa Migula. (PGPR).

Pseudomonas aeruginosa Migula is an opportunistic bacteria that lives in soil, water, and even in environments like hot tubs. In present research work studies were conducted on two cultivars of Chenopodium quinoa. Willd was treated with the Strains of Pseudomonas aeruginosa Migula cultured and maintained on nutrient agar medium. Production of the roots and root lets were affected by treatment of PGPR and high number of root lets were reported in 15 days seedlings of Chenopodium quinoa Willd. This Pseudomonas aeruginosa Migula play an important role in soil fertility thus effectively solubilizes fixed phosphorus to exchangeable form and enables solubilization of Phosphorus in soil. Natural Phosphorus solubilization of Pseudomonas aeruginosa Migula improves both plant and soil health and also aids in soil remediation. The population of beneficial Pseudomonas aeruginosa Migula increases the organic content of soil improves soil fertility. Plant Growth Promoting Rhizobacteria (PGPR), plays an important role in improving plant growth. The comprehensive understanding of bacterial plant growth promoting mechanism helps to get sustainable agriculture production under biotic and a biotic stress. PGPR are beneficial for plant growth and also referred as yield increasing bacteria. Treatments with PGPR increases germination percentage, seedling vigor, emergence, plant stand, root and shoot growth, total biomass of the plants, seed weight, early flowering, grains etc., Inoculation of Pseudomonas aeruginosa Migula in agricultural fields improves the uptake of P and N in plants with an increase in leaf chlorophyll, total soluble protein and plant biomass production.

Balanced Fertilization for Improved Nutrient use Efficiency and Mulberry Productivity

Aim: To study the effects of balanced fertilization in improving leaf yield, quality and nutrient use efficiency in mulberry. Study Design: Experiment was conducted in randomized block design (RBD) consisting of 7 treatments in 3 replications. Place and Duration of Study: The present study was conducted at Central Sericultural Research and Training Institute, Berhampore ((Latitude 24º05ʹN & Longitude 88º15ʹE; 18 m > MSL), West Bengal, India in two seasons during 2018 (July-August; September-October). Methodology: Existing S-1635 mulberry plantation (10year-old; 60 cm × 60 cm spacing; net plot area: 32 m2) was utilized. Experiments were conducted in two seasons (July-August, 2018; September-October, 2018) in randomized block design (RBD) consisting of 7 treatments in 3 replications. The treatments in this study included, T1: 100% N-P2O5-K2O+S+Zn with Urea-SSP-10:26:26 + Bentonite Sulphur (8 kg ha-1) + Zinc Sulphate (1 kg ha-1) as BF; T2: 75% BF; T3: 100% N-P2O5-K2O alone (Urea-SSP-10:26:26); T4: 75% N-P2O5-K2O alone (Urea-SSP-10:26:26); T5: 100% N-P2O5-K2O alone (Urea-DAP-MOP); T6: 100% N-P2O5-K2O alone (Urea-SSP-MOP) as farmers′ practice (FP); T7: Nutrients omission plot (Control). The recommended fertilizer dose (100%) for irrigated mulberry production in the Eastern region is N-P2O5-K2O=67-36-22 kg ha-1 crop-1. All the fertilizers were applied in two equal splits on 15th and 30th day after pruning. Results: This study reveals the importance of balanced fertilization of mulberry with N, P, K, S and Zn for sustainable productivity, which is reflected by the maximum values for leaf yield attributes, chlorophyll content and leaf yield. Further, mulberry leaf quality (in terms of total soluble protein and total soluble sugar) significantly improved with balanced fertilization. Higher PFP and AUE were also recorded with fertilization with compound/complex fertilizers than with straight fertilizers; but the balanced fertilization exhibited remarkable enhancement. Conclusion: The results prove that balanced fertilization of N-P2O5-K2O @ 67-36-22 kg ha-1 (Urea-SSP-10:26:26) with Bentonite sulphur (8 kg ha-1) and zinc sulphate (1 kg ha-1) were effective in improving mulberry productivity through enhanced nutrient use efficiency. This could be useful for realizing maximum productivity in mulberry as an efficient nutrient management strategy in mulberry cultivation.

Sustainability of Wheat (Triticum Aestivum L.) Yield and Improvement of Seed Quality Through Probiotic and Organic Soil Amendment

In search of alternative counter to harmful effects of chemical fertilizers on soils and environment, probiotic and organic manures-based fertilizer management options need to be evaluated. The experiments were designed as randomized complete block design (RCBD) consisting of three wheat varieties and nine soil amendment treatments. The result revealed that organic amendments had prominent and variable effects on studied parameters and statistically at par with chemical fertilizer. Some yield-associated parameters like spike length, spikeletsspike-1, fertile spikelets spike-1, grains spike-1, grains weight spike-1 and 1000-grain weight were significantly influenced by organic amendments. Moreover, grain yield and straw yield were increased73% and 27%, respectively under the treatment of poultry manure combination in comparison with control. In addition, the seed quality characters viz. germination, vigor index and total soluble protein content also exhibited significant improvement showing23%, 44%and 17%, respectively by poultry manure + vermicompost + green manure. The above findings showed that to apply poultry manure + vermicompost + green manure as an effective soil amendment option and to obtain good yield and quality seed of wheat. Bangladesh Agron. J. 2021, 24(1): 1-11

Beet Molasses Enhance Salinity Tolerance in Thymus serpyllum—A Study under Greenhouse Condition

The growing demand for Thymus serpyllum biomass to produce drugs, cosmetics and spices necessitates the search for innovative methods mitigating the negative effects of environmental stressors in order to improve its yield under unfavorable conditions. Due to the exposure of plants to salinity stress (SS), we investigated the effect of sugar beet molasses (SBM) on the growth and biochemical parameters related to plants’ response to SS. Wild thyme plants were treated for 5 weeks to sodium chloride and 3% molasses solution using two modes of application (soil irrigation or foliar sprays). Plants irrigated by SBM showed slighter stem growth inhibition than control plants, high stress tolerance index and maintained a constant root water content under salt stress. Moreover plants treated with 100 mM NaCl and soil-applied SBM had lower lipid peroxidation level, showed lower POD activity, higher total soluble protein content and maintained a more even free amino acids level, compared to the control treatments. The concentration of potassium ions was higher in the case of plant roots irrigation with sugar beet molasses compared to control plants. In this experiment, most of the growth and biochemical parameters from foliar molasses-sprayed plants did not differ significantly from the control. We provided evidence that soil-applied SBM beneficially changed the plant’s biochemical response to salt stress. On the basis of the obtained results, we conclude that this soil amendment contributes to the strengthening of plant protection against this harmful environmental factor.