Biological control services of agroecosystems depend on the functional diversity of species traits. However, the relationship between arthropod traits and landscape heterogeneity is still poorly understood, especially in tropical rice agroecosystems, which harbor a high diversity of often specialized species. We investigated how landscape heterogeneity, measured by three metrics of landscape composition and configuration, influenced body size, functional group composition, dispersal ability, and vertical distribution of rice arthropods in the Philippines. We found that landscape composition and configuration acted to filter arthropod traits in tropical rice agroecosystems. Landscape diversity and rice habitat fragmentation were the two main gradients influencing rice-arthropod traits, indicating that different rice arthropods have distinct habitat requirements. Whereas small parasitoids and species mostly present in the rice canopy were favored in landscapes with high compositional heterogeneity, predators and medium-sized species occupying the base of the rice plant, including planthoppers, mostly occurred in highly fragmented rice habitats. We demonstrate the importance of landscape heterogeneity as an ecological filter for rice arthropods, identifying how the different components of landscape heterogeneity selected for or against specific functional traits. However, the contrasting effects of landscape parameters on different groups of natural enemies indicate that not all beneficial rice arthropods can be promoted at the same time when using a single land management strategy. Increasing compositional heterogeneity in rice landscapes can promote parasitoids but may also negatively affect predators. Future research should focus on identifying trade-offs between fragmented rice habitats and structurally diverse landscapes to maximize the presence of multiple groups of beneficial arthropods.

• Klíčová slova
• RLQ analyses, arthropods, biological control, fourth-corner analyses, functional traits, landscape heterogeneity, rice,
• MeSH
• biodiverzita MeSH
• členovci * MeSH
• ekosystém MeSH
• rýže (rod) * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The plant genome can produce long non-coding RNAs (lncRNAs), some of which have been identified as important regulators of gene expression. To better understand the response mechanism of rice plants to Rice black-streaked dwarf virus (RBSDV) infection, we performed a comparative transcriptome analysis between the RBSDV-infected and non-infected rice plants. A total of 1342 mRNAs and 22 lncRNAs were identified to be differentially expressed after RBSDV infection. Most differentially expressed transcripts involved in the plant-pathogen interaction pathway were upregulated after RBSDV infection, indicating the activation of rice defense response by RBSDV. A network of differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) was then constructed. In this network, there are 56 plant-pathogen interaction-related DEmRNAs co-expressing with 20 DElncRNAs, suggesting these DElncRNAs and DEmRNAs may play essential roles in rice innate immunity against RBSDV. Moreover, some of the lncRNA-mRNA regulatory relationships were experimentally verified in rice calli by a quick and effective method established in this study. Three DElncRNAs were selected to be tested, and the results indicated that five mRNAs were found to be regulated by them. Together, we give a whole landscape of rice mRNAs and lncRNAs in response to RBSDV infection, and a feasible method to rapidly verify the lncRNA-mRNA regulatory relationship in rice.

• Klíčová slova
• DElncRNA, DEmRNA, gene expression regulatory network, rice, rice black-streaked dwarf virus, rice calli, transcriptome analysis,
• MeSH
• messenger RNA genetika   metabolismus   MeSH
• nemoci rostlin genetika   virologie   MeSH
• regulace genové exprese u rostlin * MeSH
• RNA dlouhá nekódující genetika   metabolismus   MeSH
• RNA rostlin genetika   metabolismus   MeSH
• rostlinné viry genetika   fyziologie   MeSH
• stanovení celkové genové exprese MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH
• RNA dlouhá nekódující MeSH
• RNA rostlin MeSH

Plants remodel their root architecture in response to a salinity stress stimulus. This process is regulated by an array of factors including phytohormones, particularly auxin. In the present study, in order to better understand the mechanisms involved in salinity stress adaptation in rice, we compared two contrasting rice cultivars-Luna Suvarna, a salt tolerant, and IR64, a salt sensitive cultivar. Phenotypic investigations suggested that Luna Suvarna in comparison with IR64 presented stress adaptive root traits which correlated with a higher accumulation of auxin in its roots. The expression level investigation of auxin signaling pathway genes revealed an increase in several auxin homeostasis genes transcript levels in Luna Suvarna compared with IR64 under salinity stress. Furthermore, protein profiling showed 18 proteins that were differentially regulated between the roots of two cultivars, and some of them were salinity stress responsive proteins found exclusively in the proteome of Luna Suvarna roots, revealing the critical role of these proteins in imparting salinity stress tolerance. This included proteins related to the salt overly sensitive pathway, root growth, the reactive oxygen species scavenging system, and abscisic acid activation. Taken together, our results highlight that Luna Suvarna involves a combination of morphological and molecular traits of the root system that could prime the plant to better tolerate salinity stress.

• Klíčová slova
• PIN, YUCCA, abiotic stress, auxin, mass spectrometry, proteomics, rice, root, salinity,
• Publikační typ
• časopisecké články MeSH

Adaxial, abaxial phylloplane (leaf), and spermoplane (seed) are proximal yet contrasting habitats for a microbiota that needs to be adequately explored. Here, we proposed novel methods to decipher the adaxial/abaxial-phylloplane and spermoplane-microbiomes. Comparison of 22 meta barcoded-NGS datasets (size of total data set-1980.48 Mb) enabled us to fine-map the microbiome of the rice foliar niche, which encompasses the lower, middle, top leaf as well panicle. Here, the total- and the cultivable-microbiome profiling revealed 157 genera representing ten phyla and 87 genera from 4 bacterial phyla, respectively, with a predominance of Proteobacteria and Actinobacteria. Interestingly, more bacterial communities (124-genera) preferred the abaxial than the adaxial phylloplane (104-genera) and spermoplane (67-genera) for colonization. The microbiome profiles were nearly identical on the aromatic (125-genera) and non-aromatic rice (116-genera) with high representation of Pantoea, Methylobacterium, Curtobacterium, Sphingopyxis, and Microbacterium. The culturomics investigation confirmed the abundance of Pantoea, Chryseobacterium, Pseudomonas, Acinetobacter, Sphingobacterium, and Exiguobacterium. One hundred bacterial isolates characterized and identified by polyphasic-taxonomic tools revealed the dominance of Acinetobacter, Chryseobacterium, Enterobacter, Massilia, Pantoea, Pseudomonas, and Stenotrophomonas on adaxial/abaxial-phylloplane and spermoplane. The study culminated in identifying hitherto unexplored bacterial communities on the adaxial/abaxial phylloplane and spermoplane of rice that can be harnessed for microbiome-assisted rice cultivation in the future.

• Klíčová slova
• Abaxial, Adaxial, Metabarcoding, Microbiome, Phylloplane, Rice, Spermoplane,
• MeSH
• genotyp MeSH
• listy rostlin mikrobiologie   MeSH
• mikrobiota * MeSH
• rýže (rod) * MeSH
• Sphingomonadaceae * MeSH
• Publikační typ
• časopisecké články MeSH

Inorganic arsenic intake is likely to affect long-term health. High concentrations are found in some rice-based foods and drinks widely used in infants and young children. In order to reduce exposure, we recommend avoidance of rice drinks for infants and young children. For all of the rice products, strict regulation should be enforced regarding arsenic content. Moreover, infants and young children should consume a balanced diet including a variety of grains as carbohydrate sources. Although rice protein-based infant formulas are an option for infants with cows' milk protein allergy, the inorganic arsenic content should be declared and the potential risks should be considered when using these products.

• MeSH
• arsen analýza   toxicita   MeSH
• chemické látky znečišťující vodu analýza   toxicita   MeSH
• dítě MeSH
• karcinogeny životního prostředí analýza   toxicita   MeSH
• kojenec MeSH
• kontaminace potravin * MeSH
• látky znečišťující půdu analýza   toxicita   MeSH
• lidé MeSH
• označování potravin MeSH
• podpora zdraví MeSH
• rýže (rod) chemie   růst a vývoj   MeSH
• semena rostlinná chemie   růst a vývoj   MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• arsen MeSH
• chemické látky znečišťující vodu MeSH
• karcinogeny životního prostředí MeSH
• látky znečišťující půdu MeSH

Selenium (Se) is a beneficial element, but only when present within its permissible range. Its hyper-accumulation in edible plant parts can cause Se toxicity. This study aimed to develop an agronomic plan for biofortification of rice with Se and reclamation of cadmium (Cd)-contaminated soil, utilizing sodium selenite (Na2SeO3) and cadmium chloride (CdCl2) as soil treatments. Biofortification was performed on two target rice varieties: genotypes 5097A/R2035 and GangYou725, in field trials by applying Cd at a concentration of 0-8 mg kg soil-1 and Se at 0-1 mg kg soil-1. Since these rice varieties have different metabolic specificity, the degree of elemental accumulation, deviations in chlorophyll concentration, activity of photosynthetic apparatus and grain yield were assessed. It was found that application of 1 mg kg-1 Se2O3 decrease Cd content and increased chlorophyll content and photosynthetic activity while grain yield was unaffected by application of the metallic trace-elements. Comparing effects at different stages, we found that the 50% heading stage was most sensitive to metal application. In sum, Se mitigates Cd toxicity, but hyperaccumulation of Se (4 mg kg-1) in polished rice was observed with Cd at 4 and 8 mg kg-1. The elevated level of Cd stress in pot experiments resulted in over-accumulation of Se in the germ and endosperm that poses serious health concerns.

• Klíčová slova
• Accumulation, Cadmium, Health-risk assessment, Morpho-physiological traits, Rice, Selenium,
• MeSH
• kadmium analýza   toxicita   MeSH
• látky znečišťující půdu * analýza   toxicita   MeSH
• půda MeSH
• rýže (rod) * MeSH
• selen * farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kadmium MeSH
• látky znečišťující půdu * MeSH
• půda MeSH
• selen * MeSH

Adaptive traits in rice responding to flooding, a compound stress, are associated with morpho-anatomical and physiological changes which are regulated at the genetic level. Therefore, understanding submergence stress tolerance in rice will help development of adapted cultivars that can help mitigate agricultural losses. Rice is an important dietary component of daily human consumption and is cultivated as a staple crop worldwide. Flooding is a compound stress which imposes significant financial losses to farmers. Flood-affected rainfed rice ecosystems led to the development of various adaptive traits in different cultivars for their optimal growth and survival. Some cultivars can tolerate hypoxia by temporarily arresting elongation and conserving their energy sources, which they utilize to regrow after the stress conditions subside. However, few other cultivars rapidly elongate to escape hypoxia using carbohydrate resources. These contrasting characters are regulated at the genetic level through different quantitative trait loci that contain ERF transcription factors (TFs), Submergence and Snorkels. TFs can simultaneously activate the transcription of various genes involved in stress and development responses. These TFs are of prime importance because the introgressed and near-isogenic lines showed promising results with increased submergence tolerance without affecting yield or quality. However, the entire landscape of submergence tolerance is not entirely depicted, and further exploration in the field is necessary to understand the mechanism in rice completely. Therefore, this review will highlight the significant adaptive traits observed in flooded rice varieties and how they are regulated mechanistically.

• Klíčová slova
• Adventitious roots, Flooding, ROL, Rice, Snorkel, Sub1A, Submergence, Waterlogging,
• MeSH
• ekosystém MeSH
• fenotyp MeSH
• fyziologická adaptace genetika   MeSH
• hypoxie genetika   MeSH
• lokus kvantitativního znaku MeSH
• rýže (rod) * fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Rice is the lifeline for more than half of the world population, and in India, in view of its huge demand in the country, farmers adopt a rice-rice cropping system where the irrigation facility is available. As rice is a nutrient-exhausting crop, sustainable productivity of rice-rice cropping system greatly depends on appropriate nutrient management in accordance with the inherent soil fertility. The application of an ample dose of fertilizer is the key factor for maintaining sustainable rice yields and nutrient balance of the soil. Considering the above facts, an experiment was conducted on nutrient management in a rice-rice cropping system at the university farm of Visva-Bharati, situated in a sub-tropical climate under the red and lateritic belt of the western part of West Bengal, India, during two consecutive years (2014-2016). The experiment was laid out in a Randomized Completely Block Design with 12 treatments and three replications, with different rates of N:P:K:Zn:S application in both of the growing seasons, namely, kharif and Boro. The recommended (ample) dose of nutrients was 80:40:40:25:20 and 120:60:60:25:20 kg ha-1 of N:P2O5:K2O:Zn:S in the Kharif and Boro season, respectively. A high yielding variety, named MTU 7029, and a hybrid, Arize 6444 GOLD, were taken in the Kharif and Boro seasons, respectively. The results clearly indicated that the application of a recommended dose of nutrients showed its superiority over the control (no fertilizer application) in the expression of growth characters, yield attributes, yields, and nutrient uptake of Kharif as well as Boro rice. Out of the all treatments, the best result was found in the treatment where the ample dose of nutrients was applied, resulting in maximum grain yield in both the Kharif (5.6 t ha-1) and Boro (6.6 t ha-1) season. The corresponding yield attributes for the same treatment in the Kharif (panicles m-2: 247.9; grains panicle-1: 132.0; spikelets panicle-1: 149.6; test weight: 23.8 g; and panicle length: 30.6 cm) and Boro (panicles m-2: 281.6; grains panicle-1: 142.7; spikelets panicle-1: 157.2; test weight: 24.8 g; and panicle length: 32.8 cm) season explained the maximum yield in this treatment. Further, a reduction or omission of individual nutrients adversely impacted on the above traits and resulted in a negative balance of the respective nutrients. The study concluded that the application of a recommended dose of nutrients was essential for proper nutrient balance and sustainable yields in the rice-rice cropping system.

• Klíčová slova
• growth characters, nutrient management, nutrient uptake and balance, productivity, rice–rice cropping system, yield attributes,
• Publikační typ
• časopisecké články MeSH

Photooxidative damage causes early leaf senescence and plant cell death. In this study, a light-sensitive rice cultivar, 812HS, and a non-light-sensitive cultivar, 812S, were used to investigate early leaf photooxidation. Leaf tips of 812HS exhibited yellowing under a light intensity of 720 μmol(photon) m-2 s-1, accompanied by a decrease in chlorophyll and carotenoids, but 812S was unaffected. The photosynthetic performance of 812HS was also poorer than that of 812S. The H2O2, O2 ·-, and malondialdehyde content increased sharply in 812HS, and associated antioxidant enzymes were inhibited. The degradation of core proteins in both PSI and PSII, as well as other photosynthesis-related proteins, was accelerated in 812HS. When shaded [180 μmol(photon) m-2 s-1], 812HS recovered to normal. Therefore, our findings suggested excess light disturbed the balance of ROS metabolism, leading to the destruction of the antioxidant system and photosynthetic organs, and thus triggering the senescence of rice leaves.

• Klíčová slova
• photooxidation, reactive oxygen species, rice, shading, thylakoid membrane proteins,
• Publikační typ
• časopisecké články MeSH

The flours from pigmented and glutinous rice have a great potential to increase the nutritional quality of gluten-free breads. The characteristics of whole-meal fine flours, slurries, doughs, and breads prepared from black, red, and white glutinous rice were, therefore, compared with commercially used refined fine and semi-coarse white rice flours. The pasting properties of different flours were strongly influenced by the type of rice they were made from. Slurries with red and glutinous flours exhibited a shift to a lower pasting temperature T0, lower values of ηPeak and ηFinal, as well as higher values of the breakdown and setback region than the slurries with refined flours. The slurry with black flour exhibited high values of viscosity η0 and breakdown, together with low values of ηFinal, setback region and total setback. Bread characteristics were strongly correlated with the pasting properties. The presence of bran particles did not negatively impact loaf volume, crumb hardness, springiness, and chewiness. Some defects were observed in glutinous and red rice bread. Fine flour exhibited better baking performance than semi-coarse flour. Glutinous flour has the potential to become an ingredient in gluten-free baking. The applicability of various black and red rice flours may be limited by the flavor and the taste.

• Klíčová slova
• applicability, black rice, bread quality, dough, glutinous rice, red rice, rheology, slurry, texture,
• Publikační typ
• časopisecké články MeSH