Higher temperatures and lower annual rainfall do not restrict, directly or indirectly, the mycorrhizal colonization of barley (Hordeum vulgare L.) under rainfed conditions

Plant-Fungi Interactions: Where It Goes?

Fungi live different lifestyles-including pathogenic and symbiotic-by interacting with living plants. Recently, there has been a substantial increase in the study of phytopathogenic fungi and their interactions with plants. Symbiotic relationships with plants appear to be lagging behind, although progressive. Phytopathogenic fungi cause diseases in plants and put pressure on survival. Plants fight back against such pathogens through complicated self-defense mechanisms. However, phytopathogenic fungi develop virulent responses to overcome plant defense reactions, thus continuing their deteriorative impacts. Symbiotic relationships positively influence both plants and fungi. More interestingly, they also help plants protect themselves from pathogens. In light of the nonstop discovery of novel fungi and their strains, it is imperative to pay more attention to plant-fungi interactions. Both plants and fungi are responsive to environmental changes, therefore construction of their interaction effects has emerged as a new field of study. In this review, we first attempt to highlight the evolutionary aspect of plant-fungi interactions, then the mechanism of plants to avoid the negative impact of pathogenic fungi, and fungal strategies to overcome the plant defensive responses once they have been invaded, and finally the changes of such interactions under the different environmental conditions.

Organic carbon accumulation and aggregate formation in soils under organic and inorganic fertilizer management practices in a rice-wheat cropping system

Soil organic carbon (C) and aggregates are the important components of soil fertility and the foundation of sustainable agriculture. The storage and protection of SOC in aggregates is widely regarded as the material basis of soil organic C accumulation. However, current understanding of soil aggregate and its associated organic C is insufficient to elucidate the regulation mechanism of soil organic C. A nine-year field experiment including chemical fertilizer (FR) and organic manure (OM) treatments was set up in the eastern plain of Funiu Mountain, central China. Using chemical analysis, physical sieving as well as nuclear magnetic resonance (NMR) methods, we mainly probed into the response of soil organic C concentration and composition, and C functional groups, water-stable aggregates to different treatments. Furthermore, scanning electronic microscopy (SEM) and partial least square structural equation modelling (PLS-SEM) was conducted to characterise the different size aggregates and to analyse the mechanism of soil organic C accumulation and stabilisation at aggregate scales. After nine years of farming, OM treatment substantially increased soil organic C content (by 3.77 g kg^-1) and significantly enhanced the formation of macro-aggregates (> 250 μm), while FR had no significant influence on soil organic C. At the aggregate scale, the amounts of soil organic C, C physical fractions (particulate and mineral-associated organic C), total nitrogen and microbial biomass carbon associated in macro-aggregates (> 250 μm) were obviously higher than that in micro-aggregates and silt + clay fraction, and OM treatment greatly increased the accumulation of soil organic C and its components in macro-aggregates. Moreover, microbial biomass carbon (MBC) amounts in aggregates were remarkably increased (27-116%) by the application of OM. And MBC had a positively effect on the physical fractions of SOC but not on the C chemical structure within aggregates. The present study indicated that soil organic C accumulation mainly rely on macro-aggregates (> 250 μm). Intra-particulate organic carbon (POC) and mineral-associated organic carbon (MOC) within macro-aggregates played an important role in soil organic C accumulation. Meanwhile, soil microbes were a driving force for the accumulation of soil organic C physical fractions (POC and MOC). We concluded that OM treatment accelerated the synergistic process between organic C sequestration and soil aggregation, and showed great potential to increase soil organic C accumulation.

Effects of Abiotic Stress on Soil Microbiome

Rhizospheric organisms have a unique manner of existence since many factors can influence the shape of the microbiome. As we all know, harnessing the interaction between soil microbes and plants is critical for sustainable agriculture and ecosystems. We can achieve sustainable agricultural practice by incorporating plant-microbiome interaction as a positive technology. The contribution of this interaction has piqued the interest of experts, who plan to do more research using beneficial microorganism in order to accomplish this vision. Plants engage in a wide range of interrelationship with soil microorganism, spanning the entire spectrum of ecological potential which can be mutualistic, commensal, neutral, exploitative, or competitive. Mutualistic microorganism found in plant-associated microbial communities assist their host in a number of ways. Many studies have demonstrated that the soil microbiome may provide significant advantages to the host plant. However, various soil conditions (pH, temperature, oxygen, physics-chemistry and moisture), soil environments (drought, submergence, metal toxicity and salinity), plant types/genotype, and agricultural practices may result in distinct microbial composition and characteristics, as well as its mechanism to promote plant development and defence against all these stressors. In this paper, we provide an in-depth overview of how the above factors are able to affect the soil microbial structure and communities and change above and below ground interactions. Future prospects will also be discussed.