Accumulation of Glycogen and Upregulation of LEA-1 in C. elegans daf-2(e1370) Support Stress Resistance, Not Longevity

DAF-16-dependent activation of a dauer-associated genetic program in the C. elegans insulin/IGF-1 daf-2(e1370) mutant leads to accumulation of large amounts of glycogen with concomitant upregulation of glycogen synthase, GSY-1. Glycogen is a major storage sugar in C. elegans that can be used as a short-term energy source for survival, and possibly as a reservoir for synthesis of a chemical chaperone trehalose. Its role in mitigating anoxia, osmotic and oxidative stress has been demonstrated previously. Furthermore, daf-2 mutants show increased abundance of the group 3 late embryogenesis abundant protein LEA-1, which has been found to act in synergy with trehalose to exert its protective role against desiccation and heat stress in vitro, and to be essential for desiccation tolerance in C. elegans dauer larvae. Here we demonstrate that accumulated glycogen is not required for daf-2 longevity, but specifically protects against hyperosmotic stress, and serves as an important energy source during starvation. Similarly, lea-1 does not act to support daf-2 longevity. Instead, it contributes to increased resistance of daf-2 mutants to heat, osmotic, and UV stress. In summary, our experimental results suggest that longevity and stress resistance can be uncoupled in IIS longevity mutants.

Genome-wide analysis of metallothionein gene family in maize to reveal its role in development and stress resistance to heavy metal

Background Maize (Zea mays L.) is a widely cultivated cereal and has been used as an optimum heavy metal phytoremediation crop. Metallothionein (MT) proteins are small, cysteine-rich, proteins that play important roles in plant growth and development, and the regulation of stress response to heavy metals. However, the MT genes for maize have not been fully analyzed so far. Methods The putative ZmMT genes were identified by HMMER.The heat map of ZmMT genes spatial expression analysis was generated by using R with the log2 (FPKM + 1).The expression profiles of ZmMT genes under three kinds of heavy metal stresses were quantified by using qRT-PCR. The metallothionein proteins was aligned using MAFFT and phylogenetic analysis were constructed by ClustalX 2.1. The protein theoretical molecular weight and pI, subcellular localization, TFs binding sites, were predicted using ProtParam, PSORT, PlantTFDB, respectively. Results A total of 9 ZmMT genes were identified in the whole genome of maize. The results showed that eight of the nine ZmMT proteins contained one highly conserved metallothio_2 domain, while ZmMT4 contained a Metallothio_PEC domain. All the ZmMT proteins could be classified into three major groups and located on five chromosomes. The ZmMT promoters contain a large number of hormone regulatory elements and hormone-related transcription factor binding sites. The ZmMT genes exhibited spatiotemporal specific expression patterns in 23 tissues of maize development stages and showed the different expression patterns in response to Cu, Cd, and Pb heavy metal stresses. Conclusions We identified the 9 ZmMT genes, and explored their conserved motif, tissue expression patterns, evolutionary relationship. The expression profiles of ZmMT genes under three kinds of heavy metal stresses (Cu, Cd, Pb) were analyzed. In summary, the expression of ZmMTs have poteintial to be regulated by hormones. The specific expression of ZmMTs in different tissues of maize and the response to different heavy metal stresses are revealed that the role of MT in plant growth and development, and stress resistance to heavy metals.

Effect of Apartment Community Garden Program on Sense of Community and Stress

Apartment housing has become a dominant form of urban residence. High dwelling density in apartment complexes causes frequent conflicts and disputes. To counter this, it is necessary to promote a sense of community among residents with programs such as a customized horticultural program for the introduction of a community garden in an apartment complex. This study was conducted to investigate the effect of a community garden program in an apartment complex in fostering residents’ sense of community and reducing stress. Experiments were performed in three groups: a group participating in the program based on the sense of community theory (SCG; n = 11), a group participating with a focus on horticultural education (HEG; n = 11), and a non-participation group (NPG; n = 10). The experimental results revealed that the sense of community was significantly higher in the SCG than in the HEG and NPG. The results suggest that the SCG positively affected the sense of community, overall energy, ratio between sympathetic and parasympathetic nervous systems, and stress resistance. Considering these results, community garden programs with appropriate interventions to promote a sense of community are more effective in improving community life and reducing stress than programs based on horticultural education.

A Simple and Low-Cost Strategy to Improve Conidial Yield and Stress Resistance of Trichoderma guizhouense through Optimizing Illumination Conditions

Light is perceived by photoreceptors in fungi and further integrated into the stress-activated MAPK HOG pathway, and thereby potentially activates the expression of genes for stress responses. This indicates that the precise control of light conditions can likely improve the conidial yield and stress resistance to guarantee the low cost and long shelf life of Trichoderma-based biocontrol agents and biofertilizers. In this study, effects of wavelengths and intensities of light on conidial yield and stress tolerance to osmotic, oxidative and pH stresses in Trichoderma guizhouense were investigated. We found that 2 μmol photons/(m2 × s) of blue light increased the conidial yield more than 1000 folds as compared to dark condition and simultaneously enhanced conidial stress resistance. The enhanced conidial stress resistance is probably due to the upregulated stress-related genes in blue light, which is under the control of the blue light receptor BLR1 and the MAP kinase HOG1.

Recent Trends in Nano-Fertilizers for Sustainable Agriculture under Climate Change for Global Food Security

Nano-fertilizers (NFs) significantly improve soil quality and plant growth performance and enhance crop production with quality fruits/grains. The management of macro-micronutrients is a big task globally, as it relies predominantly on synthetic chemical fertilizers which may not be environmentally friendly for human beings and may be expensive for farmers. NFs may enhance nutrient uptake and plant production by regulating the availability of fertilizers in the rhizosphere; extend stress resistance by improving nutritional capacity; and increase plant defense mechanisms. They may also substitute for synthetic fertilizers for sustainable agriculture, being found more suitable for stimulation of plant development. They are associated with mitigating environmental stresses and enhancing tolerance abilities under adverse atmospheric eco-variables. Recent trends in NFs explored relevant agri-technology to fill the gaps and assure long-term beneficial agriculture strategies to safeguard food security globally. Accordingly, nanoparticles are emerging as a cutting-edge agri-technology for agri-improvement in the near future. Interestingly, they do confer stress resistance capabilities to crop plants. The effective and appropriate mechanisms are revealed in this article to update researchers widely.

Effects of Food and Temperature on Drosophila melanogaster Reproductive Dormancy as Revealed by Quantification of a GFP-Tagged Yolk Protein in the Ovary

When exposed to harsh environmental conditions, such as food scarcity and/or low temperature, Drosophila melanogaster females enter reproductive dormancy, a metabolic state that enhances stress resistance for survival at the expense of reproduction. Although the absence of egg chambers carrying yolk from the ovary has been used to define reproductive dormancy in this species, this definition is susceptible to false judgements of dormancy events: e.g. a trace amount of yolk could escape visual detection; a fly is judged to be in the non-dormancy state if it has a single yolk-containing egg chamber even when other egg chambers are devoid of yolk. In this study, we propose an alternative method for describing the maturation state of oocytes, in which the amount of yolk in the entire ovary is quantified by the fluorescence intensity derived from GFP, which is expressed as a fusion with the major yolk protein Yp1. We show that yolk deposition increases with temperature with a sigmoidal function, and the quality of food substantially alters the maximum accumulation of yolk attainable at a given temperature. The Yp1::GFP reporter will serve as a reliable tool for quantifying the amount of yolk and provides a new means for defining the dormancy state in D. melanogaster.