Cadmium is a potentially toxic heavy metal that hampers plant productivity by interfering with their photochemistry. Cd causes disturbances in a range of physiological processes of plants such as photosynthesis, water relations, ion metabolism and mineral uptake. Cd pronouncedly affects photosynthesis by alteration of its vital machinery in all aspects. Photosynthesis is a well organised and sequential process fundamental to all green plants and microorganisms which involves various components, including photosynthetic pigments and photosystems, the electron transport system and CO2 reduction pathways. Any damage at any level caused by Cd, critically affects overall photosynthetic capacity. Present review focuses on key effects of Cd on photosynthetic apparatus including chloroplast structure, photosynthetic pigments, Chl-protein complexes and photosystems resulting in overall decrease in efficiency of carbon assimilation pathway.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-54-45) contains supplementary material, which is available to authorized users.

Trichoderma biopriming enhances rice growth in drought-stressed soils by triggering various plant metabolic pathways related to antioxidative defense, secondary metabolites, and hormonal upregulation. In the present study, transcriptomic analysis of rice cultivar IR64 bioprimed with Trichoderma harzianum under drought stress was carried out in comparison with drought-stressed samples using next-generation sequencing techniques. Out of the 2,506 significant (p < 0.05) differentially expressed genes (DEGs), 337 (15%) were exclusively expressed in drought-stressed plants, 382 (15%) were expressed in T. harzianum-treated drought-stressed plants, and 1,787 (70%) were commonly expressed. Furthermore, comparative analysis of upregulated and downregulated genes under stressed conditions showed that 1,053 genes (42%) were upregulated and 733 genes (29%) were downregulated in T. harzianum-treated drought-stressed rice plants. The genes exclusively expressed in T. harzianum-treated drought-stressed plants were mostly photosynthetic and antioxidative such as plastocyanin, small chain of Rubisco, PSI subunit Q, PSII subunit PSBY, osmoproteins, proline-rich protein, aquaporins, stress-enhanced proteins, and chaperonins. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis states that the most enriched pathways were metabolic (38%) followed by pathways involved in the synthesis of secondary metabolites (25%), carbon metabolism (6%), phenyl propanoid (7%), and glutathione metabolism (3%). Some of the genes were selected for validation using real-time PCR which showed consistent expression as RNA-Seq data. Furthermore, to establish host–T. harzianum interaction, transcriptome analysis of Trichoderma was also carried out. The Gene Ontology (GO) analysis of T. harzianum transcriptome suggested that the annotated genes are functionally related to carbohydrate binding module, glycoside hydrolase, GMC oxidoreductase, and trehalase and were mainly upregulated, playing an important role in establishing the mycelia colonization of rice roots and its growth. Overall, it can be concluded that T. harzianum biopriming delays drought stress in rice cultivars by a multitude of molecular programming.

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Chaetomium globosum is a potential biological control agent effective against various plant pathogens. Several reports are available on the mycoparastism and antibiosis mechanisms of C. globosum against plant pathogenic fungi, whereas a few states induced resistance. The potential induced defense component of C. globosum (Cg-2) was evaluated against early blight disease of tomato (Solanum lycopersicum) and further, global RNA sequencing was performed to gain deep insight into its mechanism. The expression of marker genes of hormone signaling pathways, such as PR1, PiII, PS, PAL, Le4, and GluB were analyzed using real-time quantitative reverse transcription PCR (qRT-PCR) to determine the best time point for RNA sequencing. The transcriptome data revealed that 22,473 differentially expressed genes (DEGs) were expressed in tomato at 12 h post Cg-2 inoculation as compared with control plants and among these 922 DEGs had a fold change of −2 to +2 with p < 0.05. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that most of the DEGs were belonging to metabolic pathways, biosynthesis of secondary metabolites, plant–pathogen interaction, chlorophyll metabolism, and plant hormone signal transduction. Gene Ontology (GO) analysis revealed that DEGs were enriched mainly related to binding activity (GO:0005488), catalytic activity (GO:0003824), metabolic process (GO:0008152), cellular process (GO:0009987), response to stimulus (GO:0050896), biological regulation (GO:0065007), and transcription regulator activity (GO:0140110). The gene modulations in hormone signaling transduction, phenylpropanoid biosynthesis, and mitogen-activated protein kinases (MPK) signaling indicated the upregulation of genes in these pathways. The results revealed active participation of jasmonic acid (JA) and salicylic acid (SA) signaling transduction pathways which further indicated the involvement of induced systemic resistance (ISR) and systemic acquired resistance (SAR) in the systemic resistance induced by Cg-2 in tomato.

Background Fusarium fujikuroi causing bakanae is one of the most signi cant pathogen of rice and much responsible for yield losses thereby emerging as a major risk to food security. Methods In the present study transcriptomic analysis was conducted between two contrasting resistant (C101A51) and susceptible (Rasi) genotypes of rice with the combinations of C101A51 control (CC) vs C101A51 inoculated (CI); Rasi control (RC) vs Rasi inoculated (RI) and C101A51 inoculated (CI) vs Rasi inoculated (RI). ResultsIn CC vs CI commonly expressed genes were 12,764. Out of them 567 (4%) were signi cantly upregulated and 1399 (9%) genes were down regulated. For the RC vs RI 14, 333 (79%) genes were commonly expressed. For CI vs RI 13,662 (72%) genes commonly expressed. Cysteine proteinase inhibitor 10, disease resistance protein TAO1-like, oleosin 16 kDa-like, pathogenesis-related protein (PR1), (PR4), BTB/POZ and MATH domain-containing protein 5-like, alpha-amylase isozyme 3D-like (LOC4345814), were upregulated in resistant genotype C101A51.Whereas, GDSL esterase/lipase At5g33370, serine glyoxylate aminotransferase, CASP-like protein 2C1, WAT1related protein At4g08290, Cytoplasmic linker associated proteins, xyloglucan endotransglucosylase/hydrolase protein and β-D xylosidase 7 were upregulated in susceptible genotype Rasi. Gene ontology analysis showed functions related to defence response (GO:0006952), regulation of plant hypersensitive type response (GO:0010363), Potassium ion transmembrane activity (GO:0015079), chloroplast (GO:0009507), response to wounding (GO:0009611), xylan biosynthetic process (GO:0045492) were upregulated in resistant genotype C101A51 under inoculated conditions. Conclusions Real time PCR based validation of the selected DEGs showed that the qRT-PCR was consistent with the RNA-Seq results. This is the rst transcriptomic study against bakanae disease of rice in Indian genotypes and will be helpful for the development of bakanae management strategies.phenotype. BTB/POZ and MATH domain proteins are upregulated in resistant genotype C101A51. Generally, BTB domain participates in plant responses against biotic and abiotic stresses. He et al, [37] reported down regulation of BTB gene under Phytophthora capsici infection. Upregulation of this gene in resistant genotype may have role in defence against F. fujikuroi.Results of the selected DEGs showed that the qRT-PCR was consistent with the RNA-Seq results showing similar expression pattern of up-and down-regulated genes by using both, RNA-Seq and qRT-PCR, analyses. ConclusionsThe results showed that general expression of glucanases, peroxidases in both, resistant and susceptible, genotypes could represent the basic defence mechanism of rice against F. fujikuroi. What was found strikingly different in resistant genotype is the modulation of WRKY transcriptional factors, Cysteine proteinase inhibitor 10 (LOC4335551), disease resistance protein TAO1-like (LOC112939055), oleosin 16 kDa-like (LOC4336570), pathogenesis-related protein (PR1), pathogenesis-related...