Estimation of Genetic Variability, Heritability and Genetic Advances for Short Duration and High Yielding Rice Genotypes

The goal of the study was to find genotypes of 18 different rice varieties that would yield a lot of rice in a short amount of time. With this in mind, the study genotypes' field performance as well as the relationships between various morpho-physiological and yield-contributing traits among the genotypes was assessed. The experiments were conducted from July to December 2018 at the Agronomy Field, Department of Agronomy and Agricultural Extension, Faculty of Agriculture, Rajshahi University. In genotype BRRI dhan 51, the maximum number of days to 50% flowering was discovered. The genotype BRRI dhan 56 had the lowest number of days required for 50% flowering. Genotypes showed a wide range of days to maturity (92.00–109.00), with an average of 98.96 days. The genotypes DRR 46, BINA 7, and DRR 44 are followed by the genotypes BRR1 dhan 66, BRR1 dhan 56, and BRR1 dhan 57, which have shorter maturity periods (i.e., 92.00 days), indicating earliness. The traits investigated in this study showed high heritabilities, with estimates ranging from 67.00 to 96.00 percent. Days to flowering and unfilled grain panicle-1 had the highest heritability among the traits (96.00%).The presence of high heritability values suggests that the expression of the traits under study is less influenced by the external environment. The unfilled grain panicle-1 had the highest genetic advance as a percentage of the mean (144.80%), while panicle length had the lowest genetic advance (10.48%) among the traits that affected yield. View Article DOI: 10.47856/ijaast.2022.v09i10.00

The Study of Genetic Divergence in Rice (Oryza Sativa L.) Genotypes with Grain Yield and Different Morpho-Physiological Traits using Mahalanobis’ D2 Analysis

The current study attempted to study genetic divergence in rice (Oryza sativa L.) genotypes with grain yield and different morpho-physiological traits among 18 rice varieties using Mahalanobis' D2 analysis. Keeping this in mind, the performance of the studied genotypes, as well as the association between various morpho-physiological and yield contributing traits among the genotypes, were evaluated in the field. The experiments were conducted from July to December 2018 at the Agronomy Field, Department of Agronomy and Agricultural Extension, Faculty of Agriculture, Rajshahi University. In terms of grain yield and other morpho-physiological traits, the genotypes differed significantly. The genotypes were classified into five clusters using Mahalonobis' D2 statistics and Tocher's method (Table 3). Cluster IV was the smallest of the clusters. Cluster l is the largest, with six genotypes. Clusters II and lV each contained three and two genotypes. The pattern of genotype distribution among various clusters reflected the significant genetic variability present in the genotypes, which may be due to adaptation of these genotypes to specific environmental conditions. Genotypes from different clusters are expected (inter-cluster). The intra (bold) and inter-cluster distances from D2 analysis (Table 4). Cluster I has the greatest intra cluster distance (0.956), while Cluster IV has the smallest (0.3583). The greatest inter-cluster distance is observed between cluster IV and (8.190), while the smallest inter-cluster distance is observed between cluster II and IV (2.924). In both vectors, the average inter-cluster distances were greater than the average intra-cluster distances, indicating the presence of greater genetic diversity among genotypes from different clusters than those from the same cluster. These findings indicated that these five traits contributed the most to the divergence among the eighteen rice genotypes. The results revealed that the clusters were remarkably distinct for the majority of the traits, indicating proper clustering. The most effective tiller, grain panicle, effective grain panicle, and days to maturity were found in Cluster V. The intra-cluster mean for grain yield was the lowest in this cluster. Cluster III had the lowest grain yield per acre. This was the cluster with the lowest initial grain yield. The intra-cluster mean for effective tiller and days to maturity was highest in this cluster. Cluster II had the smallest grain yield and the second smallest thousand grain weight. Cluster V had the shortest panicle length intra-cluster. View Article DOI: 10.47856/ijaast.2022.v09i10.00

Annexin A6 improves anti-migratory and anti-invasive properties of tyrosine kinase inhibitors in EGFR overexpressing human squamous epithelial cells

Annexin A6 (AnxA6), a member of the calcium (Ca2+ ) and membrane binding annexins, is known to stabilize and establish the formation of multifactorial signaling complexes. At the plasma membrane, AnxA6 is a scaffold for protein kinase Cα (PKCα) and GTPase-activating protein p120GAP to promote downregulation of epidermal growth factor receptor (EGFR) and Ras/mitogen-activated protein kinase (MAPK) signaling. In human squamous A431 epithelial carcinoma cells, which overexpress EGFR, but lack endogenous AnxA6, restoration of AnxA6 expression (A431-A6) promotes PKCα-mediated threonine 654 (T654)-EGFR phosphorylation, which inhibits EGFR tyrosine kinase activity. This is associated with reduced A431-A6 cell growth, but also decreased migration and invasion in wound healing, matrigel, and organotypic matrices. Here, we show that A431-A6 cells display reduced EGFR activity in vivo, with xenograft analysis identifying increased pT654-EGFR levels, but reduced tyrosine EGFR phosphorylation compared to controls. In contrast, PKCα depletion in A431-A6 tumors is associated with strongly reduced pT654 EGFR levels, yet increased EGFR tyrosine phosphorylation and MAPK activity. Moreover, tyrosine kinase inhibitors (TKIs; gefitinib, erlotinib) more effectively inhibit cell viability, clonogenic growth, and wound healing of A431-A6 cells compared to controls. Likewise, the ability of AnxA6 to inhibit A431 motility and invasiveness strongly improves TKI efficacy in matrigel invasion assays. This correlates with a greatly reduced invasion of the surrounding matrix of TKI-treated A431-A6 when cultured in 3D spheroids. Altogether, these findings implicate that elevated AnxA6 scaffold levels contribute to improve TKI-mediated inhibition of growth and migration, but also invasive properties in EGFR overexpressing human squamous epithelial carcinoma

Analysis of Genetic Diversity in Some Rice Varieties and Their Performance in Bangladesh

This study was conducted to evaluate the genetic diversity for several rice features and their association with yields, as well as to identify genotypes of short-duration rice. The experiment was conducted in the field in a natural environment, and data were collected on several plant parameters for each genotype at various phases of plant development. Twenty genotypes of rice were examined based on their morphological and physiological characteristics. From July through December of 2020, the experiment was conducted at the Bangladesh Rice Research Institute's regional station in Shyampur, Rajshahi. There was significant diversity among the twenty rice genotypes for all characteristics tested. The genotype BRRI dhan57 displayed the shortest days to flowering. In terms of days to maturity, the genotype BRRI dhan57 was the earliest, with a maturity time of 107.33 days, followed by BRRI dhan56 and BRRI dhan39. The days to blooming had the highest heritability (99.75%), followed by the days to maturity (99.58%), grain yield (85.30%), thousand grain weight (85.22%), grains per panicle (84.91%), plant height (82.21%), and tillers per hill (21.61%). High heritability scores indicated that the researched qualities were less influenced by the surrounding environment. As a percentage of the mean, the genetic gain was greatest for grain yield (36.33%) and lowest for tillers per hill (6.60%) among the yield-contributing factors. In days to flowering, days to maturity, grains per panicle, and plant height, high heritability and genetic progress were seen. According to the principal component analysis (PCA), the Eigen values of the first four components of the total variance accounted for 89.46% of the total variance, indicating that these components were mostly responsible for the genetic diversity of the current materials. It was the largest cluster, containing seven rice genotypes. Clusters II and V contained five and four genotypes of rice, respectively. Clusters III and IV were the smallest, with only two genotypes apiece. The pattern of distribution of genotypes among various clusters demonstrated the significant genetic variety present in the genotypes, which may be the result of adaptation of these genotypes to certain environmental conditions. The largest value of intercluster distance indicated that cluster III genotypes were extremely distinct from cluster IV genotypes. Negative values in both vectors for tillers per hill suggested that this feature contributed the least to the total diversity. The number of panicles per hill, panicle length, weight per thousand grains, and grain yield were all positive in both directions. According to these statistics, these four characteristics contributed the most to the variety. View Article DOI: 10.47856/ijaast.2022.v09i12.00

Annexin A6 and NPC1 regulate LDL-inducible cell migration and distribution of focal adhesions

Cholesterol is considered indispensable for cell motility, but how physiological cholesterol pools enable cells to move forward remains to be clarified. The majority of cells obtain cholesterol from the uptake of Low-Density lipoproteins (LDL) and here we demonstrate that LDL stimulates A431 squamous epithelial carcinoma and Chinese hamster ovary (CHO) cell migration and invasion. LDL also potentiated epidermal growth factor (EGF) -stimulated A431 cell migration as well as A431 invasion in 3-dimensional environments, using organotypic assays. Blocking cholesterol export from late endosomes (LE), using Niemann Pick Type C1 (NPC1) mutant cells, pharmacological NPC1 inhibition or overexpression of the annexin A6 (AnxA6) scaffold protein, compromised LDL-inducible migration and invasion. Nevertheless, NPC1 mutant cells established focal adhesions (FA) that contain activated focal adhesion kinase (pY397FAK, pY861FAK), vinculin and paxillin. Compared to controls, NPC1 mutants display increased FA numbers throughout the cell body, but lack LDL-inducible FA formation at cell edges. Strikingly, AnxA6 depletion in NPC1 mutant cells, which restores late endosomal cholesterol export in these cells, increases their cell motility and association of the cholesterol biosensor D4H with active FAK at cell edges, indicating that AnxA6-regulated transport routes contribute to cholesterol delivery to FA structures, thereby improving NPC1 mutant cell migratory behaviour

Annexin A6 and late endosomal cholesterol modulate integrin recycling and cell migration.

Annexins are a family of proteins that bind to phospholipids in a calcium-dependent manner. Earlier studies implicated annexin A6 (AnxA6) to inhibit secretion and participate in the organization of the extracellular matrix. We recently showed that elevated AnxA6 levels significantly reduced secretion of the extracellular matrix protein fibronectin (FN). Because FN is directly linked to the ability of cells to migrate, this prompted us to investigate the role of AnxA6 in cell migration. Up-regulation of AnxA6 in several cell models was associated with reduced cell migration in wound healing, individual cell tracking and three-dimensional migration/invasion assays. The reduced ability of AnxA6-expressing cells to migrate was associated with decreased cell surface expression of αVβ3 and α5β1 integrins, both FN receptors. Mechanistically, we found that elevated AnxA6 levels interfered with syntaxin-6 (Stx6)-dependent recycling of integrins to the cell surface. AnxA6 overexpression caused mislocalization and accumulation of Stx6 and integrins in recycling endosomes, whereas siRNA-mediated AnxA6 knockdown did not modify the trafficking of integrins. Given our recent findings that inhibition of cholesterol export from late endosomes (LEs) inhibits Stx6-dependent integrin recycling and that elevated AnxA6 levels cause LE cholesterol accumulation, we propose that AnxA6 and blockage of LE cholesterol transport are critical for endosomal function required for Stx6-mediated recycling of integrins in cell migration

The role of Annexin A6 in cancer cell signalling and cholesterol homeostasis

Annexin A6 (AnxA6) is a Ca2+ and phospholipid binding protein belonging to the well conserved annexin family. The phospholipid binding capacity of AnxA6, in addition to protein-protein interactions is thought to allow AnxA6 to affect membrane organisation and receptor/protein kinase function. Several cancer models showed a correlation between loss of AnxA6 and elevated epidermal growth factor receptor (EGFR)/Ras activity. Enhanced growth signalling and alterations in lipid biosynthesis, uptake and transport are implicated in the transformation events leading to cancer initiation and tumour progression. Thus, the identification of potential mediators of these cellular processes could provide better understanding of cancer cell biology and perhaps the development of new, rationalised drug targets. The central aim of this study was to examine AnxA6, as a scaffold protein that links cell signalling and cholesterol homeostasis in an oncogenic setting. To examine the role of AnxA6 in an oncogenic context, A431 epidermoid carcinoma cells, overexpressing AnxA6, were used in cancer growth assays and cell viability assays. AnxA6 overexpression correlated with increased membrane recruitment of protein kinase Cα (PKCα), a negative regulator of the EGFR, and PKCα-mediated inactivation of EGFR via phosphorylation of the EGFR inhibitory residue threonine 654 (T654-EGFR). Increased T654 phosphorylation translated to reduced cell growth in cell culture and in vivo xenograft models, in a PKCα-dependent manner. AnxA6 overexpression also correlated with reduced migration and invasion in 2D and 3D-in vivo-like settings. Furthermore, AnxA6 increased the potency of EGFR tyrosine kinase inhibitors, gefitinib and erlotinib to decrease cancer cell growth and migration, indicating its potential as biomarker for drug efficacy. AnxA6 is known to regulate cholesterol transport along endo- and exocytic pathways. This is exemplified in AnxA6 overexpressing cells, which represent a Niemann Pick Type C 1 (NPC1)-like phenotype, which is characterised by late endosomal (LE)-cholesterol accumulation and depletion of cholesterol at other cellular locations, such as the plasma membrane and the Golgi. To investigate the role of AnxA6 in intracellular cholesterol homeostasis, we used Chinese Hamster Ovary (CHO) cell lines lacking functional NPC1. Loss of NPC1 activity, akin to AnxA6 overexpression, correlated with reduced cell migration, reduced activation of migration signalling cascades and mislocalisation of receptors/kinases known to promote cell adhesion and spreading. Furthermore, alterations in cholesterol homeostasis were associated with increased potency of anti-cancer agents to decrease cell migration. Thus, AnxA6 alters both EGFR signal output and cholesterol-dependent membrane trafficking events, reflecting its cooperative involvement as a scaffold in signal transduction and its ability to interact with cholesterol-dependent partners. This study further exemplifies dual functions of AnxA6 in cancer cell signalling and cholesterol homeostasis

The cross-talk of LDL-cholesterol with cell motility: Insights from the Niemann Pick Type C1 mutation and altered integrin trafficking

Cholesterol is considered indispensible for the recruitment and functioning of integrins in focal adhesions for cell migration. However, the physiological cholesterol pools that control integrin trafficking and focal adhesion assembly remain unclear. Using Niemann Pick Type C1 (NPC) mutant cells, which accumulate Low Density lipoprotein (LDL)-derived cholesterol in late endosomes (LE), several recent studies indicate that LDL-cholesterol has multiple roles in regulating focal adhesion dynamics. Firstly, targeting of endocytosed LDL-cholesterol from LE to focal adhesions controls their formation at the leading edge of migrating cells. Other newly emerging literature suggests that this may be coupled to vesicular transport of integrins, Src kinase and metalloproteases from the LE compartment to focal adhesions. Secondly, our recent work identified LDL-cholesterol as a key factor that determines the distribution and ability of several Soluble NSF Attachment Protein (SNAP) Receptor (SNARE) proteins, key players in vesicle transport, to control integrin trafficking to the cell surface and extracellular matrix (ECM) secretion. Collectively, dietary, genetic and pathological changes in cholesterol metabolism may link with efficiency and speed of integrin and ECM cell surface delivery in metastatic cancer cells. This commentary will summarize how direct and indirect pathways enable LDL-cholesterol to modulate cell motility

COMPARISON OF GROWTH AND YIELD PERFORMANCE OF RICE VARIETIES UNDER THREE AGRO ECOLOGICAL ZONE

<p>The experiment was conducted to study “COMPARISON OF GROWTH AND YIELD PERFORMANCE OF RICE VARIETIES UNDER THREE AGR0ECOLOGICAL ZONE”. The experiment consisted of five varieties viz, two inbred variety; BRRI dhan-28, BRRI dhan-29 and three hybrid variety: Surma-2, BRRI hybrid dhan-2, Hira-5; three regions viz. Rajshahi, Rangpur and Bogra. The experiment was laid out in a randomized complete block design with three replications. Among the tested varieties BRRI dhan-29 produced highest grain yield (7.97 t ha<sup>-1</sup>) which was significantly superior to all other varieties and lowest grain yield (5.21 t ha<sup>-1</sup>) was produced Surma-2 in Rajshahi region. Hira-5 produced highest grain yield (8.81 t ha<sup>-1</sup>) which was significantly superior to all other varieties and lowest grain yield (6.40 t ha<sup>-1</sup>) was produced BRRI dhan-28 in Rangpur region. Surma-2 produced highest grain yield (9.48 tha<sup>-1</sup>) which was significantly superior to all other varieties and BRRI dhan-28 produced the lowest grain yield (6.79 t ha<sup>-1</sup>) in Bogra region. All the yield contributing measurements of rice varieties showed variability in different region. The result summarized that hybrid variety showed superior performance in comparison with inbred variety (2010-2011).</p&gt

USE OF HERVICIDES FOR WEED CONTROL AND THEIR EFFECTS ON YIELD PERFORMANCE OF WHEAT (Triticum aestivum L)

<p>This experiment was carried out in the research farm of the Regional Wheat Research Institute, Shampur, Rajshahi during the period from November last week 2019 to April first week 2020 in order to the find out “USE OF HERVICIDES FOR WEED CONTROL AND THEIR EFFECTS ON YIELD PERFORMANCE OF WHEAT (Triticum aestivum L) .’’ Wheat sown both conventional and strip method. In this research yield and yield contributing characters were found and maximum wheat production observed by under strip tillage method (4.48 t/ha). In randomized complete block design (RCBD) with three replications in both tillage systems with some herbicides were tested for weed control treatment. The maximum number of effective and total tiller per meter square, 1000 grain weight, were observed in T<sub>4</sub>(Affinity, BD.) herbicides for weed control treatment. As a result, maximum grain yield was obtained in T<sub>4</sub> treatment. The 2<sup>nd</sup> maximum yield was recorded in T<sub>6 </sub>(Axial + Affinity, India) herbicides for weed control treatment. The lowest grain and other yield contributing characters were found in T<sub>9 </sub>(Weedy check) condition. The effect of interaction between different method of cultivation and weed control treatment were insignificant for all yield and yield contributing characters except plant height, grain yield and straw yield.</p&gt