Stripe rust disease of wheat, caused by Puccinia striiformis f. sp. tritici, (Pst) is one of the most serious diseases of wheat worldwide. In India, virulent stripe rust races have been constantly ...evolving in the North-Western Plains Zone leading to the failure of some of the most widely grown resistant varieties in the region. With the goal of studying the recent evolution of virulent races in this region, we conducted whole-genome re-sequencing of three prevalent Indian Pst pathotypes Pst46S119, Pst78S84 and Pst110S119. We assembled 58.62, 58.33 and 55.78 Mb of Pst110S119, Pst46S119 and Pst78S84 genome, respectively and found that pathotypes were highly heterozygous. Comparative phylogenetic analysis indicated the recent evolution of pathotypes Pst110S119 and Pst78S84 from Pst46S119. Pathogenicity-related genes classes (CAZyme, proteases, effectors, and secretome proteins) were identified and found to be under positive selection. Higher rate of gene families expansion were also observed in the three pathotypes. A strong association between the effector genes and transposable elements may be the source of the rapid evolution of these strains. Phylogenetic analysis differentiated the Indian races in this study from other known United States, European, African, and Asian races. Diagnostic markers developed for the identification of three Pst pathotypes will help tracking of yellow rust at farmers field and strategizing resistance gene deployment.
Leaf rust caused by Puccinia triticina is the most common and widely distributed of the three wheat rusts. Losses from leaf rust are usually less damaging than those from stem rust and stripe rust, ...but leaf rust causes greater annual losses due to its more frequent and widespread occurrence. Yield losses from leaf rust are mostly due to reductions in kernel weight. Many laboratories worldwide conduct leaf rust surveys and virulence analyses. Most currently important races (pathotypes) have either evolved through mutations in existing populations or migrated from other, often unknown, areas. Several leaf rust resistance genes are cataloged, and high levels of slow rusting adult plant resistance are available in high yielding CIMMYT wheats. This paper summarizes the importance of leaf rust in the main wheat production areas as reflected by yield losses, the complexity of virulence variation in pathogen populations, the role cultivars with race-specific resistance play in pathogen evolution, and the control measures currently practiced in various regions of the world.
The progress of leaf rust research in wheat Prasad, Pramod; Savadi, Siddanna; Bhardwaj, S.C. ...
Fungal biology,
June 2020, 2020-Jun, 2020-06-00, 20200601, Letnik:
124, Številka:
6
Journal Article
Recenzirano
Leaf rust (also called brown rust) in wheat, caused by fungal pathogen Puccinia triticina Erikss. (Pt) is one of the major constraints in wheat production worldwide. Pt is widespread with diverse ...population structure and undergoes rapid evolution to produce new virulent races against resistant cultivars that are regularly developed to provide resistance against the prevailing races of the pathogen. Occasionally, the disease may also take the shape of an epidemic in some wheat-growing areas causing major economic losses. In the recent past, substantial progress has been made in characterizing the sources of leaf rust resistance including non-host resistance (NHR). Progress has also been made in elucidating the population biology of Pt and the mechanisms of wheat-Pt interaction. So far, ∼80 leaf rust resistance genes (Lr genes) have been identified and characterized; some of them have also been used for the development of resistant wheat cultivars. It has also been shown that a gene-for-gene relationship exists between individual wheat Lr genes and the corresponding Pt Avr genes so that no Lr gene can provide resistance unless the prevailing race of the pathogen carries the corresponding Avr gene. Several Lr genes have also been cloned and their products characterized, although no Avr gene corresponding a specific Lr gene has so far been identified. However, several candidate effectors for Pt have been identified and functionally characterized using genome-wide analyses, transcriptomics, RNA sequencing, bimolecular fluorescence complementation (BiFC), virus-induced gene silencing (VIGS), transient expression and other approaches. This review summarizes available information on different aspects of the pathogen Pt, genetics/genomics of leaf rust resistance in wheat including cloning and characterization of Lr genes and epigenetic regulation of disease resistance.
•Wheat leaf rust (WLR) is one of the major constraints to wheat production.•∼80 Lr genes have been identified and used in breeding.•Molecular basis of wheat-Pt interaction has been discovered in several cases.•Nature of Lr genes & their interaction with effectors are being interpreted.•The review discusses QTLs, Pt biology, genomics, effectoromics, epigenetics.
Theoretical investigation on propagation dynamics of an elliptical
q
-Gaussian laser beam in a plasma by considering the relativistic mass nonlinearity of plasma electrons has been presented. The ...study is then extended to investigate the electron plasma wave (EPW) excitation by the laser beam. Following variational theory the nonlinear wave equations governing the evolution of laser beam and plasma wave have been reduced to a set of coupled ordinary differential equations for the beam widths of pump beam and EPW. Further the acceleration of electrons by the EPW excited by the laser beam has been investigated. The results obtained from numerical analysis reveal a stronger self-focusing of the
q
-Gaussian laser beam, which is desirable to excite a large amplitude electron plasma wave (EPW) for electron acceleration by extending the interaction length.
Biosensors are emerging as efficient (sensitive and selective) and affordable analytical diagnostic tools for early-stage disease detection, as required for personalized health wellness management. ...Low-level detection of a targeted disease biomarker (pM level) has emerged extremely useful to evaluate the progression of disease under therapy. Such collected bioinformatics and its multi-aspects-oriented analytics is in demand to explore the effectiveness of a prescribed treatment, optimize therapy, and correlate biomarker level with disease pathogenesis. Owing to nanotechnology-enabled advancements in sensing unit fabrication, device integration, interfacing, packaging, and sensing performance at point-of-care (POC) has rendered diagnostics according to the requirements of disease management and patient disease profile i.e. in a personalized manner. Efforts are continuously being made to promote the state of art biosensing technology as a next-generation non-invasive disease diagnostics methodology. Keeping this in view, this progressive opinion article describes personalized health care management related analytical tools which can provide access to better health for everyone, with overreaching aim to manage healthy tomorrow timely. Considering accomplishments and predictions, such affordable intelligent diagnostics tools are urgently required to manage COVID-19 pandemic, a life-threatening respiratory infectious disease, where a rapid, selective and sensitive detection of human beta severe acute respiratory system coronavirus (SARS-COoV-2) protein is the key factor.
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•Investigated efficient miniaturized nano-enabled sensors are suitable for POC diagnostics.•Smartphone assisted POC diagnostics is making personalized diagnostics possible.•AI is managing bioinformatics and big data analytics to optimize personalized wellness.•AI supported IoT-based diagnostics is emerging for targeted disease management.•AI and IoT assisted POC diagnostics are needed for COVID-19 pandemic management.
The bound state solutions to the radial Schrödinger equation are obtained in three-dimensional space using the series expansion method within the framework of a general interaction potential. The ...energy eigenvalues of the pseudoharmonic and Kratzer potentials are given as special cases. The obtained analytical results are applied to several diatomic molecules, i.e.
N
2
,
CO
,
NO
and
CH
. In order to check the accuracy of the present method, a comparison is made with similar results obtained in the literature by using other techniques.
An algorithm for characterizing attosecond extreme ultraviolet pulses that is not bandwidth-limited, requires no interpolation of the experimental data, and makes no approximations beyond the ...strong-field approximation is introduced. This approach fully incorporates the dipole transition matrix element into the retrieval process. Unlike attosecond retrieval methods such as phase retrieval by omega oscillation filtering (PROOF), or improved PROOF, it simultaneously retrieves both the attosecond and infrared (IR) pulses, without placing fundamental restrictions on the IR pulse duration, intensity or bandwidth. The new algorithm is validated both numerically and experimentally, and is also found to have practical advantages. These include an increased robustness to noise, and relaxed requirements for the size of the experimental dataset and the intensity of the streaking pulse.
The present work deals with the solutions to the radial Schrodinger equation for harmonic plus screened Kratzer potential (HSKP) within the framework of the Nikiforov-Uvarov functional analysis ...method. The Greene-Aldrich approximation is used to handle the inverse square terms of the HSKP. Reducing the HSKP into Kratzer and screened Kratzer potentials, the energy spectra of selected diatomic molecules, i.e. LiH, HCl,
$ {\rm O}_2 $
O
2
and
$ {\rm I}_2 $
I
2
are computed. Further, the equations for expectation values of several parameters, including inverse of position (
$ r^{-1} $
r
−
1
), square of inverse of position (
$ r^{-2} $
r
−
2
), kinetic energy (T) and the square of momentum (
$ p^2 $
p
2
) are obtained invoking the Hellmann-Feynman theorem. Results of this study are consistent with other similar previous studies. The analytical expressions for partition function and other thermodynamic properties of the diatomic molecules are determined.
This work presents the solutions to the non-relativistic Schrödinger equation for the generalised Cornell potential using the Nikiforov-Uvarov functional analysis method and the Greene-Aldrich ...approximation. Energy eigenvalues and eigen functions are obtained in closed form. Eigenvalue spectra of some physical potentials are also deduced from the generalised results. Further, within the framework of the Kratzer and the Coulomb perturbed potentials, two variants of the generalised potential, energy eigenvalue spectra of diatomic molecules viz CH, ScH, N
, I
and H
and the mass spectra of
and
mesons are determined, respectively. We also compute the expectation values of position inverse and its square, kinetic energy, and square of momentum for the above diatomic molecules by employing the Hellman-Feynman theorem. A close agreement is observed between the present results and some other past works.
Leaf rust is one of the important diseases limiting global wheat production and productivity. To identify quantitative trait nucleotides (QTNs) or genomic regions associated with seedling and adult ...plant leaf rust resistance, multilocus genome-wide association studies (ML-GWAS) were performed on a panel of 400 diverse wheat genotypes using 35 K single-nucleotide polymorphism (SNP) genotyping assays and trait data of leaf rust resistance. Association analyses using six multi-locus GWAS models revealed a set of 201 significantly associated QTNs for seedling and 65 QTNs for adult plant resistance (APR), explaining 1.98-31.72% of the phenotypic variation for leaf rust. Among these QTNs, 51 reliable QTNs for seedling and 15 QTNs for APR were consistently detected in at least two GWAS models and were considered reliable QTNs. Three genomic regions were pleiotropic, each controlling two to three pathotype-specific seedling resistances to leaf rust. We also identified candidate genes, such as leucine-rich repeat receptor-like (LRR) protein kinases, P-loop containing nucleoside triphosphate hydrolase and serine-threonine/tyrosine-protein kinases (STPK), which have a role in pathogen recognition and disease resistance linked to the significantly associated genomic regions. The QTNs identified in this study can prove useful in wheat molecular breeding programs aimed at enhancing resistance to leaf rust and developing next-generation leaf rust-resistant varieties.
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