Linkage Mapping of Stem Saccharification Digestibility in Rice

Rice is the staple food of almost half of the world population, and in excess 90% of it is grown and consumed in Asia, but the disposal of rice straw poses a problem for farmers, who often burn it in the fields, causing health and environmental problems. However, with increased focus on the development of sustainable biofuel production, rice straw has been recognized as a potential feedstock for non-food derived biofuel production. Currently, the commercial realization of rice as a biofuel feedstock is constrained by the high cost of industrial saccharification processes needed to release sugar for fermentation. This study is focused on the alteration of lignin content, and cell wall chemotypes and structures, and their effects on the saccharification potential of rice lignocellulosic biomass. A recombinant inbred lines (RILs) population derived from a cross between the lowland rice variety IR1552 and the upland rice variety Azucena with 271 molecular markers for quantitative trait SNP (QTS) analyses was used. After association analysis of 271 markers for saccharification potential, 1 locus and 4 pairs of epistatic loci were found to contribute to the enzymatic digestibility phenotype, and an inverse relationship between reducing sugar and lignin content in these recombinant inbred lines was identified. As a result of QTS analyses, several cell-wall associated candidate genes are proposed that may be useful for marker-assisted breeding and may aid breeders to produce potential high saccharification rice varieties

Water–fertilizer coupling effect on the growth traits of winter wheat under conditions of light and small sprinklers

Light and small sprinklers were used to irrigate winter wheat fields. The distribution and migration of water and nitrogen in soil during winter wheat growth period were analyzed. Moreover, the growth traits of winter wheat were monitored. It is demonstrated that water–fertilizer coupling effect had a significant impact on the migration of water and nitrogen in soil and the growth traits of winter wheat under conditions of light and small sprinklers. Under the same condition of irrigation quota, although the content of moisture in soil was slightly reduced with the increase of the amount of fertilizer, the impact of the amount of fertilizer on the content of moisture in soil is much more insignificant than that of irrigation quota. The content of nitrate nitrogen (NO3--N) in soil was increased with an increasing amount of fertilizer, especially when the value of irrigation quota was low. On the other hand, under the same condition of amount of fertilizer, the content of nitrate nitrogen (NO3--N) in soil was decreased with an increasing value of irrigation quota, especially when the value of irrigation quota was high. Hence, an ultra-high value of irrigation quota will aggravate the leach of nitrate nitrogen in soil. The water–fertilizer coupling effect and yield of winter wheat could be optimized by improving irrigation scheme, optimizing irrigation quota, and optimizing the amount of fertilizer

The Influence of Instrumental Line Shape Degradation on Gas Retrievals and Observation of Greenhouse Gases in Maoming, China

The instrument line shape (ILS), as a very important parameter, has a significant influence on the inversion of trace gas concentration. Different levels of ILS degradation for H2O, CO2, CH4, and CO gases were investigated, and the influence of ILS on the inversion of column-averaged dry air mole fractions (DMFs) was assessed. Our results indicate that the averages of XH2O, XCH4, and XCO with modulation efficiency (ME) amplitude values have a positive correlation, the correlation coefficients are 0.9925, 0.9968, and 0.9981 respectively, whereas the relationship between the average of XCO2 and ME is a negative correlation with 0.986 correlation coefficient. For a typical ILS degradation, a decrease of 5% in the modulation efficiency amplitude value results in the average of XCO2 changing by 0.744%, XCH4 and XH2O are less sensitive species, with average values of −0.206% and −0.464%, whereas XCO shows the strongest intraday variability with an average value of −0.238%. However, with a decrease of 2‰ in the phase error (PE) value, the average of XCO changed by −0.150%, XCO2 and XH2O almost coincided with the same average value of −0.141%, whereas XCH4 was the least sensitive species with an average value of −0.133%. At the same time, we measured the ILS for EM27/SUN spectrometers—the mean values of modulation efficiency amplitudes and phase errors were 0.9611 and 0.00593. Compared with standard values, the modulation efficiency amplitudes and the phase error deviations were 2.450% and 0.433%. During the observation period, the daily average of XCO2 ranged from 415.09 to 421.78 ppm. XCH4 ranged from 1.96 to 2.02 ppm with a mean of 1.982 ppm, and the daily average of XCO ranged from 0.118 to 0.157 ppm with a mean of 0.137 ppm. For the relationship between XCO2 and XCH4, the linear regression line shows a good correlation with the correlation coefficient R2 ≥ 0.5. Especially, for the correlation coefficient R2 = 0.82 on 8 October, our studies found a weak correlation in the variation of CO2 and CO during the observations. The correlation coefficient R2 ≥ 0.5 was only found on 30 September and 3 October. The trajectories dram at a height of 10 km give a hint of trace gas transport from the bay of western India, Bengal, and the Arabian Sea, whereas for the trajectories dram boundary layer height, trace gases were transported from southwest and east of China. These results provide a theoretical basis to understand the time and space distribution and the changes of greenhouse gas in the atmosphere as well as providing a theoretical basis for calculations of atmospheric radiation transmission

The Patent Foramen Ovale and Migraine: Associated Mechanisms and Perspectives from MRI Evidence

Migraine is a common neurological disease with a still-unclear etiology and pathogenesis. Patent foramen ovale (PFO) is a kind of congenital heart disease that leads to a right-to-left shunt (RLS). Although previous studies have shown that PFO has an effect on migraine, a clear conclusion about the link between PFO and migraine is lacking. We first summarized the PFO potential mechanisms associated with migraine, including microembolus-triggered cortical spreading depression (CSD), the vasoactive substance hypothesis, impaired cerebral autoregulation (CA), and a common genetic basis. Further, we analyzed the changes in brain structure and function in migraine patients and migraine patients with PFO. We found that in migraine patients with PFO, the presence of PFO may affect the structure of the cerebral cortex and the integrity of white matter, which is mainly locked in subcortical, deep white matter, and posterior circulation, and may lead to changes in brain function, such as cerebellum and colliculus, which are involved in the processing and transmission of pain. In summary, this paper provides neuroimaging evidence and new insights into the correlation between PFO and migraine, which will help to clarify the etiology and pathogenesis of migraine, and aid in the diagnosis and treatment of migraine in the future

Distributed Feedback Interband Cascade Laser Based Laser Heterodyne Radiometer for Column Density of HDO and CH₄ Measurements at Dunhuang, Northwest of China

Remote sensing of HDO and CH4 could provide valuable information on environmental and climatological studies. In a recent contribution, we reported a 3.53 μm distributed feedback (DFB) inter-band cascade laser (ICL)-based heterodyne radiometer. In the present work, we present the details of measurements and inversions of HDO and CH4 at Dunhuang, Northwest of China. The instrument line shape (ILS) of laser heterodyne radiometer (LHR) is discussed firstly, and the spectral resolution is about 0.004 cm−1 theoretically according to the ILS. Furthermore, the retrieval algorithm, optimal estimation method (OEM), combined with LBLRTM (Line-by-line Radiative Transfer Model) for retrieving the densities of atmospheric HDO and CH4 are investigated. The HDO densities were retrieved to be less than 1.0 ppmv, while the CH4 densities were around 1.79 ppmv from 20 to 24 July 2018. The correlation coefficient of water vapor densities retrieved by LHR and EM27/SUN is around 0.6, the potential reasons for the differences were discussed. Finally, in order to better understand the retrieval procedure, the Jacobian value and the Averaging Kernels are also discussed

Genome-Wide Identification of the RsSWEET Gene Family and Functional Analysis of <i>RsSWEET17</i> in Root Growth and Development in Radish

SWEET (Sugars Will Eventually be Exported Transporter) genes play essential roles in various biological processes, including phloem loading, sugar efflux, plant development and stress response. In this study, a total of 33 RsSWEET gene members were identified in the radish genome. They could be divided into four subfamilies and are distributed on eight radish chromosomes. Cis-acting regulatory element analysis indicated that these RsSWEET genes were potentially involved in the radish growth and development and stress response process, including circadian control and light response and responses to numerous stresses, including low-temperature and drought stress. Transcriptome data analysis revealed that a number of RsSWEET genes exhibited specific expression patterns in different tissues and developmental stages of radish. Moreover, several RsSWEET genes (e.g., RsSWEET2a, RsSWEET3a, RsSWEET16b and RsSWEET17) showed differential expression profiles under various abiotic stresses, including cold, heat, salt, Cd and Pb stress. Remarkably, the RsSWEET17 was specifically expressed in the cambium of radish. RsSWEET17 was heterologously expressed in yeast strain EBY.VW4000, which suggested that it has the ability to transport sugar. Notably, RsSWEET17-overexpressing Arabidopsis plants exhibited excessive root length, greater fresh weight and higher soluble sugar content (SSC) accumulation compared with wild-type (WT) plants, indicating that RsSWEET17 might positively regulate radish taproot development by strategically manipulating sugar accumulation. Collectively, these results clarify the molecular mechanisms underlying RsSWEET-mediated sugar accumulation and root growth and development in radish

Genome-Wide Identification of Sucrose Transporter Genes and Functional Analysis of RsSUC1b in Radish (Raphanus sativus L.)

In most higher plants, sucrose is the significant form of carbohydrate for long-distance transportation. Sucrose transporters/sucrose carriers (SUTs/SUCs) are involved in the loading and unloading of sucrose in phloem and play an important role in the growth and development of plants. In this study, 12 RsSUC genes were first identified from the radish genome, and their phylogenetic relationships, gene structure, and conserved motifs were further analyzed. RT-qPCR results indicated that RsSUC genes exhibited various expression patterns in different tissues and development stages of the radish. Overexpression of RsSUC1b in Arabidopsis significantly improved the uptake efficiency of exogenous sucrose, and promoted leaves and lateral root growth. In addition, the transgenic plants flowered significantly earlier than wild-type (WT) plants, and the soluble sugar contents (SSCs) including sucrose, glucose, and fructose in the mature leaves and pods were increased. It could be inferred that RsSUC1b is a plasma membrane sucrose transporter and plays a vital role in sucrose transportation and sugar accumulation during plant growth and development. These findings provided novel insights into the biological function of RsSUC genes and facilitate dissecting the molecular mechanism underlying sugar transport during radish development

Cys2/His2-type Zinc Finger Proteins Regulate Plant Growth and Development

Critical Reviews in Plant Sciences415351-36

Genome-Wide Identification of Sucrose Transporter Genes and Functional Analysis of <i>RsSUC1b</i> in Radish (<i>Raphanus sativus</i> L.)

In most higher plants, sucrose is the significant form of carbohydrate for long-distance transportation. Sucrose transporters/sucrose carriers (SUTs/SUCs) are involved in the loading and unloading of sucrose in phloem and play an important role in the growth and development of plants. In this study, 12 RsSUC genes were first identified from the radish genome, and their phylogenetic relationships, gene structure, and conserved motifs were further analyzed. RT-qPCR results indicated that RsSUC genes exhibited various expression patterns in different tissues and development stages of the radish. Overexpression of RsSUC1b in Arabidopsis significantly improved the uptake efficiency of exogenous sucrose, and promoted leaves and lateral root growth. In addition, the transgenic plants flowered significantly earlier than wild-type (WT) plants, and the soluble sugar contents (SSCs) including sucrose, glucose, and fructose in the mature leaves and pods were increased. It could be inferred that RsSUC1b is a plasma membrane sucrose transporter and plays a vital role in sucrose transportation and sugar accumulation during plant growth and development. These findings provided novel insights into the biological function of RsSUC genes and facilitate dissecting the molecular mechanism underlying sugar transport during radish development