Superiority of native soil core microbiomes in supporting plant growth.

Native core microbiomes represent a unique opportunity to support food provision and plant-based industries. Yet, these microbiomes are often neglected when developing synthetic communities (SynComs) to support plant health and growth. Here, we study the contribution of native core, native non-core and non-native microorganisms to support plant production.

Limited dependence on soil nitrogen fixation as subtropical forests develop.

Soil nitrogen (N) fixation, driven by microbial reactions, is critical to support the entrance of nitrogen in nutrient poor and pioneer ecosystems. However, how and why N fixation and soil diazotrophs evolve as forests develop remain poorly understood. Here, we used a 60-year forest rewilding chronosequence and found that soil N fixation activity gradually decreased with increasing forest age, experiencing dramatic drops of 64.

Host Plant Selection Imprints Structure and Assembly of Fungal Community along the Soil-Root Continuum.

The soil fungal community plays pivotal roles in soil nutrient cycling and plant health and productivity in agricultural ecosystems. However, the differential adaptability of soil fungi to different microenvironments (niches) is a bottleneck limiting their application in agriculture. Hence, the understanding of ecological processes that drive fungal microbiome assembly along the soil-root continuum is fundamental to harnessing the plant-associated microbiome for sustainable agriculture.

High-Throughput Sequencing Reveals the Regulatory Networks of Transcriptome and Small RNAs During the Defense Against in Poplar.

MicroRNAs are implicated in the adjustment of gene expression in plant response to biotic stresses. However, the regulatory networks of transcriptome and miRNAs are still poorly understood. In the present study, we ascertained the induction of genes for small RNA biosynthesis in poplar defense to a hemibiotrophic fungus and afterward investigated the molecular regulatory networks by performing comprehensive sequencing analysis of mRNAs and small RNAs in -inoculated leaves.

Jasmonic Acid- and Ethylene-Induced Mitochondrial Alternative Oxidase Stimulates Marssonina brunnea Defense in Poplar.

Mitochondrial processes are implicated in plant response to biotic stress caused by viruses, actinomyces, bacteria and pests, but their function in defense against fungal invasion remains unclear. Here, we investigated the role and regulation of mitochondrial alternative oxidase (AOX) in response to black spot disease caused by the hemibiotrophic fungus Marssonina brunnea in poplar. M.

Epigallocatechin-3-gallate enhances tomato resistance to tobacco mosaic virus by modulating RBOH1-dependent HO signaling.

Tobacco mosaic virus (TMV) is one of the most damaging plant viruses from an economic and research point of view. Epigallocatechin-3-Gallate (EGCG), a flavonoid type secondary metabolite can selectively improve plant defense against pathogens; however, the effect of EGCG on plant defense against TMV and the underlying mechanism(s) remain elusive. In this study, exogenous EGCG application increased plant resistance to TMV as revealed by significantly decreased transcript levels of TMV-coat protein (CP) in tomato leaves.

Cysteine and methionine contribute differentially to regulate alternative oxidase in leaves of poplar (Populus deltoides x Populus euramericana 'Nanlin 895') seedlings exposed to different salinity.

The effects of different doses of NaCl on the expression profiles of genes involved in the mitochondrial electron transport chain (miETC), HO and O levels, and antioxidant enzymes and amino acid metabolism were investigated in the leaves of poplar (Populus deltoides x Populus euramericana 'Nanlin 895'). In the miETC, complexes II and III and bypasses of the cytochrome c pathway including AOX and UCP displayed higher transcript abundance, whereas COX6b encoding cytochrome c oxidase were suppressed at 200 and 400 mM. HO accumulated at 200 mM NaCl but O was generated at 400 mM.

The relationship between the plant-encoded RNA-dependent RNA polymerase 1 and alternative oxidase in tomato basal defense against Tobacco mosaic virus.

Salicylic acid (SA) plays a critical role in plant defense against pathogen attack. The SA-induced viral defense in plants is distinct from the pathways mediating bacterial and fungal defense, which is pathogenesis-related protein-independent but involves an RNA-dependent RNA polymerase 1 (RDR1)-mediated RNA silencing mechanism and/or an alternative oxidase (AOX)-associated defense pathway. However, the relationship between these two viral defense-related pathways remains unclear.

Salicylic acid binding of mitochondrial alpha-ketoglutarate dehydrogenase E2 affects mitochondrial oxidative phosphorylation and electron transport chain components and plays a role in basal defense against tobacco mosaic virus in tomato.

Salicylic acid (SA) plays a critical role in plant defense against pathogen invasion. SA-induced viral defense in plants is distinct from the pathways mediating bacterial and fungal defense and involves a specific pathway mediated by mitochondria; however, the underlying mechanisms remain largely unknown. The SA-binding activity of the recombinant tomato (Solanum lycopersicum) alpha-ketoglutarate dehydrogenase (Slα-kGDH) E2 subunit of the tricarboxylic acid (TCA) cycle was characterized.

Stimulated leaf dark respiration in tomato in an elevated carbon dioxide atmosphere.

It is widely accepted that leaf dark respiration is a determining factor for the growth and maintenance of plant tissues and the carbon cycle. However, the underlying effect and mechanism of elevated CO2 concentrations ([CO2]) on dark respiration remain unclear. In this study, tomato plants grown at elevated [CO2] showed consistently higher leaf dark respiratory rate, as compared with ambient control plants.

The role of hydrogen peroxide and nitric oxide in the induction of plant-encoded RNA-dependent RNA polymerase 1 in the basal defense against Tobacco mosaic virus.

Plant RNA-dependent RNA Polymerase 1 (RDR1) is an important element of the RNA silencing pathway in the plant defense against viruses. RDR1 expression can be elicited by viral infection and salicylic acid (SA), but the mechanisms of signaling during this process remains undefined. The involvement of hydrogen peroxide (H2O2) and nitric oxide (NO) in RDR1 induction in the compatible interactions between Tobacco mosaic tobamovirus (TMV) and Nicotiana tabacum, Nicotiana benthamiana, and Arabidopsis thaliana was examined.

Flexible change and cooperation between mitochondrial electron transport and cytosolic glycolysis as the basis for chilling tolerance in tomato plants.

To find if cytosolic glycolysis dynamical metabolism plays a role in mediating respiration homeostasis and its relationship with mitochondrial electron transport chain (miETC) flexibility, we selected two tomato genotypes that differ in chilling tolerance and compared the responses of miETC, cytosolic glycolysis and respiratory homeostasis at 7 °C. Our results showed that the transcripts of both classical and bypass component genes for miETC and glycolysis were comparable for both genotypes when grown at 25 °C. However, there was a rapid global increase in the expression of most respiratory genes in response to chilling at 7 °C for both genotypes.

The reduction of reactive oxygen species formation by mitochondrial alternative respiration in tomato basal defense against TMV infection.

The role of mitochondrial alternative oxidase (AOX) and the relationship between systemic AOX induction, ROS formation, and systemic plant basal defense to Tobacco mosaic virus (TMV) were investigated in tomato plants. The results showed that TMV inoculation significantly increased the level of AOX gene transcripts, ubiquinone reduction levels, pyruvate content, and cyanide-resistant respiration (CN-resistant R) in upper, un-inoculated leaves. Pretreatment with potassium cyanide (KCN, a cytochrome pathway inhibitor) greatly increased CN-resistant R and reduced reactive oxygen species (ROS) formation, while application of salicylhydroxamic acid (SHAM, an AOX inhibitor) blocked the AOX activity and enhanced the production of ROS in the plants.