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Rice (Oryza sativa L.) is a staple food for more than half of the global population. Various abiotic and biotic stresses lead to accumulation of reactive oxygen species in rice, which damage macromolecules and signaling pathways. Rice has evolved a variety of antioxidant systems, including glutaredoxin (GRX), that protect against various stressors. A total of 48 GRX gene loci have been identified on 11 of the 12 chromosomes of the rice genome; none were found on chromosome 9. GRX proteins were classified into four categories according to their active sites: CPYC, CGFS, CC, and GRL. In this paper, we summarized the recent research advances regarding the roles of GRX in rice development regulation and response to stresses, and discussed future research perspectives related to rice production. This review could provide information for rice researchers on the current status of the GRX and serve as guidance for breeding superior varieties.

Rice blast is one of the most important diseases of rice, causing significant economic losses to agricultural production. A new gene, Pigm-1, which is allelic to Pigm, was cloned from Shuangkang 77009 using map based cloning. However, it is unclear whether there is a difference in the resistance spectrum between Pigm and Pigm-1. In this study, using 195 rice blast isolates collected from different areas of the Fujian Province, the Pigm-1 and Pigm single gene lines were inoculated to test their resistance. There was only one blast fungus JL-37 that showed a differential response in Pigm and Pigm-1 single gene lines, while the remaining 194 showed no difference. To further explore the application range of Pigm-1, the resistant rice R20-4 containing Pigm-1 was used as the donor, and a sensitive sticky rice S19-118 was used as the receptor. The hybrid F1 was first backcrossed with S19-118 using a molecular marker-assisted selection breeding method, and a strain containing the Pigm-1 gene was selected to continue to backcross with S19-118 until BC3F1. A new blast resistance rice material, Xiannuo 23, containing Pigm-1 was developed and confirmed by laboratory and field tests. This material can be broadly used for the future breeding of rice blast resistant cultivars to reduce the loss of rice production.

Global warming affects crop growth and development, threatening food security. As one of the essential food crops, rice is severely affected by high temperature stress, which compromises both its yield and quality. Therefore, gaining a deep understanding of the molecular mechanisms by which rice responds to heat stress and breeding rice varieties that are tolerant to such stress is crucial for maintaining food security. This review summarizes the impacts of heat stress on yield and quality-related traits at different growth and development stages of rice, the molecular mechanisms of rice perception and response to heat stress, and the improvement in and breeding of heat-tolerant rice varieties using existing superior alleles/QTLs. We also discuss the opportunities and challenges in creating highly heat-tolerant rice germplasm, providing new ideas and insights for the future breeding of heat-tolerant rice varieties.

Animal personality and behavioral syndromes can have profound effects on individual fitness. Consequently, there is growing recognition that knowledge of these phenomena may assist with animal conservation. Here we review evidence for personality and behavioral syndromes in amphibians (the most threatened vertebrate class), critique experimental approaches, and explore whether knowledge in this domain might assist with endangered species management. Despite being a neglected field (research has spanned just 24 species), there is emerging evidence that frogs, toads, salamanders, and newts show personality and behavioral syndromes along three behavioral axes: boldness, exploration, and activity. Among vertebrates, amphibians are unique in having a biphasic lifecycle defined by metamorphosis and obvious transformations in morphology, physiology, and habitat use, characteristics that enable detailed examination of behavioral changes across life stages and ecological contexts. Accordingly, recent work has started to make important contributions to our understanding of the development and proximate causes of personality and behavioral syndromes, with some emerging evidence for ontogenetic stability, genetic control, and state-dependent personality. To date, however, no study has considered the conservation implications of personality for amphibians. Drawing on a conceptual framework and empirical literature for all vertebrates, we argue that there is considerable potential for knowledge of animal personality to improve amphibian conservation programs. We propose a novel paradigm to improve (i) the mating and reproductive success of captive animals by ensuring that breeding pairs are behaviorally compatible and (ii) the post-reintroduction survival and reproductive potential of animals by facilitating the selection of optimal behavioral types for release.

Atlantic ghost crabs ( Ocypode quadrata ) are predators of beach-nesting shorebird nests and chicks on the United States’ Atlantic and Gulf coasts. Ghost crabs may also disturb birds, altering foraging, habitat use, or nest and brood attendance patterns. Shorebird conservation strategies often involve predator and disturbance management to improve reproductive success, but efforts rarely target ghost crabs. Despite the threat to shorebird reproductive success, ghost crabs are a poorly understood part of the beach ecosystem and additional knowledge about ghost crab habitat selection is needed to inform shorebird conservation. We monitored ghost crab activity, defined as burrow abundance, throughout the shorebird breeding season on Metompkin Island, Virginia, an important breeding site for piping plovers ( Charadrius melodus ) and American oystercatchers ( Haematopus palliatus ). We counted burrows at shorebird nests and random locations throughout the breeding season and investigated whether ghost crab activity was greater at nest sites relative to random locations without shorebird nests. While we observed burrows at all nest sites ( n = 63 nests), we found that burrow counts were lower at piping plover nests with shell cover, relative to random locations with no shell cover. Ghost crabs may avoid piping plover nest sites due to anti-predator behaviors from incubating adults or differences in microhabitat characteristics selected by piping plovers. We also investigated the effects of habitat type, date, and air temperature on the abundance of ghost crab burrows. We found that while crab burrows were present across the barrier island landscape, there were more burrows in sandy, undisturbed habitats behind the dunes, relative to wave-disturbed beach. Additionally, ghost crab activity increased later in the shorebird breeding season. Understanding when and where ghost crabs are most likely to be active in the landscape can aid decision-making to benefit imperiled shorebird populations.

Determining space use for species is fundamental to understanding their ecology, and tracking animals can reveal insights into their spatial ecology on home ranges and territories. Recent technological advances have led to GPS-tracking devices light enough for birds as small as ~30 g, creating novel opportunities to remotely monitor fine-scale movements and space use for these smaller species. We tested whether miniaturized GPS tags can allow us to understand space use of migratory birds away from their capture sites and sought to understand both pre-breeding space use as well as territory and habitat use on the breeding grounds. We used GPS tags to characterize home ranges on the breeding grounds for a migratory songbird with limited available breeding information, the Golden-crowned Sparrow ( Zonotrichia atricapilla ). Using GPS points from 23 individuals across 26 tags (three birds tagged twice), we found home ranges in Alaska and British Columbia were on average 44.1 ha (95% kernel density estimate). In addition, estimates of territory sizes based on field observations (mean 2.1 ha, 95% minimum convex polygon [MCP]) were three times smaller than 95% MCPs created using GPS tags (mean 6.5 ha). Home ranges included a variety of land cover classes, with shrubland particularly dominant (64–100% of home range cover for all but one bird). Three birds tracked twice returned to the same breeding area each year, supporting high breeding site fidelity for this species. We found reverse spring migration for five birds that flew up to 154 km past breeding destinations before returning. GPS-tracking technology allowed for critical ecological insights into this migratory species that breeds in very remote locations.

Plant-derived protein sources are the most relevant substitutes for fishmeal in aquafeeds. Nevertheless, the effects of plant based diets on the intestinal microbiome especially of juvenile Rainbow trout (Oncorhynchus mykiss) are yet to be fully investigated. The present study demonstrates, based on 16S rDNA bacterial community profiling, that the intestinal microbiome of juvenile Rainbow trout is strongly affected by dietary plant protein inclusion levels. After first feeding of juveniles with either 0%, 50% or 97% of total dietary protein content derived from plants, statistically significant differences of the bacterial gut community for the three diet-types were detected, both at phylum and order level. The microbiome of juvenile fish consisted mainly of the phyla Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria, and thus fits the salmonid core microbiome suggested in previous studies. Dietary plant proteins significantly enhanced the relative abundance of the orders Lactobacillales, Bacillales and Pseudomonadales. Animal proteins in contrast significantly promoted Bacteroidales, Clostridiales, Vibrionales, Fusobacteriales and Alteromonadales. The overall alpha diversity significantly decreased with increasing plant protein inclusion levels and with age of experimental animals. In order to investigate permanent effects of the first feeding diet-type on the early development of the microbiome, a diet change was included in the study after 54 days, but no such effects could be detected. Instead, the microbiome of juvenile trout fry was highly dependent on the actual diet fed at the time of sampling.

Ecological niche theory predicts sympatric species to show segregation in their spatio‐temporal habitat utilization or diet as a strategy to avoid competition. Similarly, within species individuals may specialize on specific dietary resources or foraging habitats. Such individual specialization seems to occur particularly in environments with predictable resource distribution and limited environmental variability. Still, little is known about how seasonal environmental variability affects segregation of resources within species and between closely related sympatric species. The aim of the study was to investigate the foraging behaviour of three closely related and sympatrically breeding fulmarine petrels (Antarctic petrels Thalassoica antarctica, cape petrels Daption capense and southern fulmars Fulmarus glacialoides) in a seasonally highly variable environment (Prydz Bay, Antarctica) with the aim of assessing inter‐ and intraspecific overlap in utilized habitat, timing of foraging and diet and to identify foraging habitat preferences. We used GPS loggers with wet/dry sensors to assess spatial habitat utilization over the entire breeding season. Trophic overlap was investigated using stable isotope analysis based on blood, feathers and egg membranes. Foraging locations were identified using wet/dry data recorded by the GPS loggers and expectation‐maximization binary clustering. Foraging habitat preferences were modelled using generalized additive models and model cross‐validation. During incubation and chick‐rearing, the utilization distribution of all three species overlapped significantly and species also overlapped in the timing of foraging during the day—partly during incubation and completely during chick‐rearing. Isotopic centroids showed no significant segregation between at least two species for feathers and egg membranes, and among all species during incubation (reflected by blood). Within species, there was no individual specialization in foraging sites or environmental space. Furthermore, no single environmental covariate predicted foraging activity along trip trajectories. Instead, best‐explanatory environmental covariates varied within and between individuals even across short temporal scales, reflecting a highly generalist behaviour of birds. Our results may be explained by optimal foraging theory. In the highly productive but spatio‐temporally variable Antarctic environment, being a generalist may be key to finding mobile prey—even though this increases the potential for competition within and among sympatric species. This article shows a striking case of closely related and sympatrically breeding species overlapping in their resource use across multiple dimensions. The very unusual results are best explained by high food availability in combination with spatio‐temporal environmental variability and mobile prey fields, requiring predators to respond opportunistically and show generalist foraging behaviour.