Pattern of Protein Expression in Developing Wheat Grains Identified through Proteomic Analysis

Grain development is one of the biological processes, which contributes to the final grain yield. To understand the molecular changes taking place during the early grain development, we profiled proteomes of two common wheat cultivars P271 and Chinese Spring (CS) with large and small grains, respectively at three grain developmental stages (4, 8, and 12 days post anthesis). An iTRAQ (isobaric tags for relative and absolute quantitation) based proteomics approach was used for this purpose. More than 3,600 proteins were reported to accumulate during early grain development in both wheat cultivars. Of these 3,600 proteins, 130 expressed differentially between two wheat cultivars, and 306 exhibited developmental stage-specific accumulation in either or both genotypes. Detailed bioinformatic analyses of differentially expressed proteins (DEPs) from the large- and small-grain wheat cultivars underscored the developmental differences observed between them and shed light on the molecular and cellular processes contributing to these differences. In silico localization of either or both sets of DEPs to wheat chromosomes exhibited a biased genomic distribution with chromosome 4D contributing largely to it. These results corresponded well with the earlier studies, performed in common wheat, where chromosome 4D was reported to harbor QTLs for yield contributing traits specifically grain length. Collectively, our results provide insight into the molecular processes taking place during early grain development, a knowledge, which may prove useful in improving wheat grain yield in the future

Broad targeting of resistance to apoptosis in cancer

Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Effects of Growth Stage-Based Limited Irrigation Management on Soil CO₂ and N₂O Emissions, Winter Wheat Yield and Nutritional Quality

Water scarcity and poor irrigation practices limit crop productivity and increase greenhouse gas (GHG) emissions in arid Northwest China. Therefore, we investigated the effects of five growth stage-based deficit irrigation strategies on the yield, quality, and greenhouse gas emissions of winter wheat. Across treatments, CO2 emissions ranged from 3824.93 to 4659.05 kg ha−1 and N2O emissions from 3.96 to 4.79 kg ha−1. Compared with CK (irrigation in all growth stages), GHG emissions decreased significantly in T1, T2, T3, and T4 (p −1. The grain protein content decreased in the order T4 > T3 > T1 > T2 > CK. On the basis of a catastrophe progression method evaluation, we recommend T1 as the irrigation practice for winter wheat, because it maintained a high grain yield and quality and reduced GHG emissions. Thus, in practice, soil moisture should be sufficient before sowing, and adequate water should be supplied during the heading and filling stages of winter wheat. This study provides a theoretical basis for exploring the irrigation strategies of high-yield, good-quality, and emission reduction of winter wheat

Effects of Growth Stage-Based Limited Irrigation Management on Soil CO2 and N2O Emissions, Winter Wheat Yield and Nutritional Quality

Water scarcity and poor irrigation practices limit crop productivity and increase greenhouse gas (GHG) emissions in arid Northwest China. Therefore, we investigated the effects of five growth stage-based deficit irrigation strategies on the yield, quality, and greenhouse gas emissions of winter wheat. Across treatments, CO2 emissions ranged from 3824.93 to 4659.05 kg ha−1 and N2O emissions from 3.96 to 4.79 kg ha−1. Compared with CK (irrigation in all growth stages), GHG emissions decreased significantly in T1, T2, T3, and T4 (p < 0.05). Water stress reduced the wheat yield, compared with CK, but the decrease depended on the stage without irrigation. Across treatments, the wheat yield was between 5610 and 6818 kg ha−1. The grain protein content decreased in the order T4 > T3 > T1 > T2 > CK. On the basis of a catastrophe progression method evaluation, we recommend T1 as the irrigation practice for winter wheat, because it maintained a high grain yield and quality and reduced GHG emissions. Thus, in practice, soil moisture should be sufficient before sowing, and adequate water should be supplied during the heading and filling stages of winter wheat. This study provides a theoretical basis for exploring the irrigation strategies of high-yield, good-quality, and emission reduction of winter wheat

Application of the steady-state principle of constant-head well permeameter to indirect subsurface drip irrigation

Weixia, Z., Huanjie, C., Zhenhua, Z. and Zhijie, S 2009. Application of the steady-state principle of constant-head well permeameter to indirect subsurface drip irrigation. Can. J. Soil Sci. 89: 671-676. Indirect subsurface drip irrigation (ISDI) is a method of increasing the irrigation water use efficiency of drip irrigation without the need to bury irrigation tubes and wet the soil surface. A major problem of ISDI is the mismatch between emitter discharge rate and water-conducting device dimension, which will result in over-filling of application water. In this paper, we propose to use the steady-state principle of Coll stant-head well permeameter (CHWP) to quantify the relationship between emitter discharge rate and water-conducting device dimension For ISDI. CHWP tests and ISDI tests were carried out in a 300 in 2 winter wheat fallow to verify its feasibility. The steady-state characteristic of these two methods was also studied using long-term infiltration. Results indicate that the equilibration time (110 min) in the ISDI tests was greater than that in the CHWP tests (30 min). The steady ponded depth in ISDI had a smaller variation than the steady water discharge rate in the CHWP. When using the steady-state principle of CHWP to design ISDI systems, there was significant linear correlation between predicted and measured ponded depth values (R(2) = 0.8379). The soil field-saturated hydraulic conductivity calculated by these two tests was approximately equal. These results demonstrate that the steady-state principle of CHWP could be used to select appropriate irrigation systems for ISDI, and ISDI provides another technique to obtain the field-saturated hydraulic conductivity

Irrigation Combined with Aeration Promoted Soil Respiration through Increasing Soil Microbes, Enzymes, and Crop Growth in Tomato Fields

Soil respiration (Rs) is one of the major components controlling the carbon budget of terrestrial ecosystems. Aerated irrigation has been proven to increase Rs compared with the control, but the mechanisms of CO2 release remain poorly understood. The objective of this study was (1) to test the effects of irrigation, aeration, and their interaction on Rs, soil physical and biotic properties (soil water-filled pore space, temperature, bacteria, fungi, actinomycetes, microbial biomass carbon, cellulose activity, dehydrogenase activity, root morphology, and dry biomass of tomato), and (2) to assess how soil physical and biotic variables control Rs. Therefore, three irrigation levels were included (60%, 80%, and 100% of full irrigation). Each irrigation level contained aeration and control. A total of six treatments were included. The results showed that aeration significantly increased total root length, dry biomass of leaf, stem, and fruit compared with the control (p < 0.05). The positive effect of irrigation on dry biomass of leaf, fruit, and root was significant (p < 0.05). With respect to the control, greater Rs under aeration (averaging 6.2% increase) was mainly driven by soil water-filled pore space, soil bacteria, and soil fungi. The results of this study are helpful for understanding the mechanisms of soil CO2 release under aerated subsurface drip irrigation

Response of Soil N₂O Emissions to Soil Microbe and Enzyme Activities with Aeration at Two Irrigation Levels in Greenhouse Tomato (<i>Lycopersicon esculentum Mill.</i>) Fields

Aerated irrigation is proven to increase soil N2O emissions; however, the mechanisms of N2O release are still unknown. A field experiment for two consecutive greenhouse tomato-growing seasons, from August 2016 to July 2017, was carried out to examine (1) the differences of aeration and irrigation on soil N2O emissions with a static chamber GC technique, and on soil physical and biotic parameters, and (2) the response of soil N2O emissions to soil physical and biotic parameters. Two irrigation levels were included: 60% (low irrigation) and 100% (high irrigation) of the full irrigation amount. Each irrigation level contained aeration and control, totaling four treatments. During the two growing seasons, soil N2O emissions with aeration were 4.5% higher than the control (p &gt; 0.05). Soil N2O emissions under the high irrigation were 13.8% greater than under the low irrigation, and the difference was significant in 2017 (p &lt; 0.05). Aeration and irrigation had positive effects on the mean soil nitrifier abundance and mean soil urease activity, and the impact of irrigation on urease was significant in 2016 (p = 0.001). In addition, aeration negatively influenced the mean soil denitrifier abundance, while irrigation positively influenced the mean soil denitrifier abundance. Regression analysis showed that the soil water-filled pore space, temperature, and denitrifier abundance were primary factors influencing soil N2O fluxes. This study provides a further understanding of the processes affecting soil N2O emissions and N dynamics, which may assist in developing mitigation strategies to reduce N2O emissions