Multiphase dynamics in a three dimensional branching network

Abstract The article aims at understanding the complex unsteady fluid dynamics in six generations of a human bronchial tree, which comprises of 63 straight sections and 31 bifurcation modules in a complete breathing cycle. The effects of 3-D arrangement on oscillatory flow is analyzed. Unsteady effects are maximum during the shift of expiration to inspiration and vice versa. It is also observed that the symmetry of the flow in cased of fully developed flow is destroyed due to unsteady effects. The flow division at the bifurcations causes a large asymmetry in the flow field during the inspiration than during the expiration process at the same cross-sections, thus displaying irreversibility of fluid dynamics. The second part of the study is aimed at analyzing the multiphase fluid dynamics inside a six generation bronchial tree for the case of an active smoker. Both the velocity magnitude contours and volume fractions of air and smoke is analyzed and it is observed that the general symmetry of the flow in the main two halves of the branching network is lost due to the interaction of smoke and air in the branches during inhalation and exhalation. It is also observed that higher mass of smoke is accumulated within the daughter branches which are at a lesser angular deviation with the trachea, whereas the branches at the extreme ends have little to no smoke deposit. This phenomenon can be attributed to the high smoke particulate density compared to that of air.</jats:p

HopA1 Effector from Pseudomonas syringae pv syringae Strain 61 Affects NMD Processes and Elicits Effector-Triggered Immunity

Pseudomonas syringae-secreted HopA1 effectors are important determinants in host range expansion and increased pathogenicity. Their recent acquisitions via horizontal gene transfer in several non-pathogenic Pseudomonas strains worldwide have caused alarming increase in their virulence capabilities. In Arabidopsis thaliana, RESISTANCE TO PSEUDOMONAS SYRINGAE 6 (RPS6) gene confers effector-triggered immunity (ETI) against HopA1pss derived from P. syringae pv. syringae strain 61. Surprisingly, a closely related HopA1pst from the tomato pathovar evades immune detection. These responsive differences in planta between the two HopA1s represents a unique system to study pathogen adaptation skills and host-jumps. However, molecular understanding of HopA1′s contribution to overall virulence remain undeciphered. Here, we show that immune-suppressive functions of HopA1pst are more potent than HopA1pss. In the resistance-compromised ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) null-mutant, transcriptomic changes associated with HopA1pss-elicited ETI are still induced and carry resemblance to PAMP-triggered immunity (PTI) signatures. Enrichment of HopA1pss interactome identifies proteins with regulatory roles in post-transcriptional and translational processes. With our demonstration here that both HopA1 suppress reporter-gene translations in vitro imply that the above effector-associations with plant target carry inhibitory consequences. Overall, with our results here we unravel possible virulence role(s) of HopA1 in suppressing PTI and provide newer insights into its detection in resistant plants.</jats:p

HopA1 Effector from Pseudomonas syringae pv syringae Strain 61 Affects NMD Processes and Elicits Effector-Triggered Immunity

Pseudomonas syringae-secreted HopA1 effectors are important determinants in host range expansion and increased pathogenicity. Their recent acquisitions via horizontal gene transfer in several non-pathogenic Pseudomonas strains worldwide have caused alarming increase in their virulence capabilities. In Arabidopsis thaliana, RESISTANCE TO PSEUDOMONAS SYRINGAE 6 (RPS6) gene confers effector-triggered immunity (ETI) against HopA1pss derived from P. syringae pv. syringae strain 61. Surprisingly, a closely related HopA1pst from the tomato pathovar evades immune detection. These responsive differences in planta between the two HopA1s represents a unique system to study pathogen adaptation skills and host-jumps. However, molecular understanding of HopA1′s contribution to overall virulence remain undeciphered. Here, we show that immune-suppressive functions of HopA1pst are more potent than HopA1pss. In the resistance-compromised ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) null-mutant, transcriptomic changes associated with HopA1pss-elicited ETI are still induced and carry resemblance to PAMP-triggered immunity (PTI) signatures. Enrichment of HopA1pss interactome identifies proteins with regulatory roles in post-transcriptional and translational processes. With our demonstration here that both HopA1 suppress reporter-gene translations in vitro imply that the above effector-associations with plant target carry inhibitory consequences. Overall, with our results here we unravel possible virulence role(s) of HopA1 in suppressing PTI and provide newer insights into its detection in resistant plants

THE EXPRESSION OF SELECTED DROUGHT RESPONSIVE GENES OF MAIZE IS INFLUENCED BY ENDOPHYTIC BACTERIAL INOCULATION

Plants respond to abiotic stresses through a series of molecular, cellular and physiological changes. These responses are further influenced by the interactions between host plant and the associated rhizospheric and endophytic microorganisms. The endophytic microorganisms, due to their intimate proximity with the host plant, are considered to have major influence on plant’s physiological responses. In the present study, three drought tolerant and plant growth promoting maize seed endophytic bacteria, Bacillus sp. MSEB 17, Bacillus sp. MSEB 72 and Bacillus sp. MSEB 78 were used as seed inoculants in maize (var Bioseed 9681) under drought stress conditions in a growth chamber pot study and their influence on four drought responsive genes (Zmdhn1, GRMZM2G055844, GRMZM2G467339 and GRMZM2G109448) in maize leaves was studied by real time PCR using specific primers. The influence of inoculation on host plant’s response to drought was evident from altered expression of target genes when compared with uninoculated plants. Notably, inoculation with MSEB 17 increased the expression of three target genes, Zmdhn1 (dehydrin) gene, GRMZM2G467339 gene and GRMZM2G109448 gene by several folds.  This study revealed the role of endophytic in alleviating the effect of drought stress in maize plants through regulating plant growth and physiological response.</jats:p