QTL controlling fiber quality traits under salt stress in upland cotton (Gossypium hirsutum L.).

KEY MESSAGE: QTL for fiber quality traits under salt stress discerned candidate genes controlling fatty acid metabolism. Salinity stress seriously affects plant growth and limits agricultural productivity of crop plants. To dissect the genetic basis of response to salinity stress, a recombinant inbred line population was developed to compare fiber quality in upland cotton (Gossypium hirsutum L.) under salt stress and normal conditions. Based on three datasets of (1) salt stress, (2) normal growth, and (3) the difference value between salt stress and normal conditions, 51, 70, and 53 QTL were mapped, respectively. Three QTL for fiber length (FL) (qFL-Chr1-1, qFL-Chr5-5, and qFL-Chr24-4) were detected under both salt and normal conditions and explained 4.26%, 9.38%, and 3.87% of average phenotypic variation, respectively. Seven genes within intervals of two stable QTL (qFL-Chr1-1 and qFL-Chr5-5) were highly expressed in lines with extreme long fiber. A total of 35 QTL clusters comprised of 107 QTL were located on 18 chromosomes and exhibited pleiotropic effects. Thereinto, two clusters were responsible for improving five fiber quality traits, and 6 influenced FL and fiber strength (FS). The QTL with positive effect for fiber length exhibited active effects on fatty acid synthesis and elongation, but the ones with negative effect played passive roles on fatty acid degradation under salt stress.

Molecular identification and functional characterization of GhAMT1.3 in ammonium transport with a high affinity from cotton (Gossypium hirsutum L.).

Ammonium (NH4 + ) represents a primary nitrogen source for many plants, its effective transport into and between tissues and further assimilation in cells determine greatly plant nitrogen use efficiency. However, biological components involved in NH4 + movement in woody plants are unclear. Here, we report kinetic evidence for cotton NH4 + uptake and molecular identification of certain NH4 + transporters (AMTs) from cotton (Gossypium hirustum). A substrate-influx assay using 15 N-isotope revealed that cotton possessed a high-affinity transport system with a Km of 58 µM for NH4 + . Sequence analysis showed that GhAMT1.1-1.3 encoded respectively a membrane protein containing 485, 509 or 499 amino acids. Heterologous functionality test demonstrated that GhAMT1.1-1.3 expression mediated NH4 + permeation across the plasma membrane (PM) of yeast and/or Arabidopsis qko-mutant cells, allowing a growth restoration of both mutants on NH4 + . Quantitative PCR measurement showed that GhAMT1.3 was expressed in roots and leaves and markedly up-regulated by N-starvation, repressed by NH4 + resupply and regulated diurnally and age-dependently, suggesting that GhAMT1.3 should be a N-responsive gene. Importantly, GhAMT1.3 expression in Arabidopsis improved plant growth on NH4 + and enhanced total nitrogen accumulation (∼50% more), conforming with the observation of 2-fold more NH4 + absorption by GhAMT1.3-transformed qko plant roots during a 1-h root influx period. Together with its targeting to the PM and saturated transport kinetics with a Km of 72 µM for NH4 + , GhAMT1.3 is suggested to be a high-affinity NH4 + permease that may play a significant role in cotton NH4 + acquisition and utilization, adding a new member in the plant AMT family.

[Establishment and Application of Model for Determining Oil Content of Cottonseed Using Near Infrared Spectroscopy].

Cotton is one of the important oil crops, and it is great significance for screening and identification of breeding materials to establish a method of the rapid, nondestructive testing of cotton seed oil content. In this study, near-infrared diffuse reflection spectroscopy of 118 high and low oil materials were adopted to establish models for fast nondestructive determining oil content of cottonseed using near infrared spectroscopy (NIR). One hundred and six cottonseed samples as calibration set that covered the range of seed oil content for upland cotton were used in this experiment. The spectral data of cottonseed were processed using the first derivative and multiplicative scatter correction (MSC). The correction NIR model of oil content was built based on partial least squares (PLS) method with the spectral regions 5 446-8 848 cm(-1) and main components (5). The determination coefficient (R2) of calibration model was 0.975, standard error of calibration (SEC) was 0.67. The authors test the model's actual ability to predict using external validation set. The correlation coefficient (r) of predicted values and the chemistry value was 0.978, the range of prediction error was 0.1% - 1.7%. The model established has good predictability. The oil content of 784 breeding stocks were predicted by NIR model, statistical analysis of predictable. results elucidated that the NIR model of oil content developed can be well applied to selective breeding and oil related study in cotton.

Analysis of retinal arteriolar and venular parameters in primary open angle glaucoma.

AIM: To measure the retinal vessels of primary open angle glaucoma (POAG) patients on spectral domain optical coherence tomography (SD-OCT) with a full-width at half-maximum (FWHM) algorithm to better explore their structural changes in the pathogenesis of POAG. METHODS: In this retrospective case-control study, the right eyes of 32 patients with POAG and 30 healthy individuals were routinely selected. Images of the supratemporal and infratemporal retinal vessels in the B zones were obtained by SD-OCT, and the edges of the vessels were identified by the FWHM method. The internal and external diameters, wall thickness (WT), wall cross-sectional area (WCSA) and wall-to-lumen ratio (WLR) of the blood vessels were studied. RESULTS: Compared with the healthy control group, the POAG group showed a significantly reduced retinal arteriolar outer diameter (RAOD), retinal arteriolar lumen diameter (RALD) and WSCA in the supratemporal (124.22±12.42 vs 138.32±10.73 µm, 96.09±11.09 vs 108.53±9.89 µm, and 4762.02±913.51 vs 5785.75±1148.28 µm2, respectively, all P<0.05) and infratemporal regions (125.01±15.55 vs 141.57±10.77 µm, 96.27±13.29 vs 110.83±10.99 µm, and 4925.56±1302.88 vs 6087.78±1061.55 µm2, all P<0.05). The arteriolar WT and WLR were not significantly different between the POAG and control groups, nor were the retinal venular outer diameter (RVOD), retinal venular lumen diameter (RVLD) or venular WT in the supratemporal or infratemporal region. There was a positive correlation between the arteriolar parameters and visual function. CONCLUSION: In POAG, narrowing of the supratemporal and infratemporal arterioles and a significant reduction in the WSCA is observed, while the arteriolar WT and WLR do not change. Among the venular parameters, the external diameter, internal diameter, WT, WLR, and WSCA of the venules are not affected.