Transcriptome analysis and genome-wide identification of the dehydration-responsive element binding gene family in jackfruit under cold stress.

BACKGROUND: Jackfruit (Artocarpus heterophyllus Lam.) is the world's largest and heaviest fruit and adapts to hot, humid tropical climates. Low-temperature injury in winter is a primary abiotic stress, which affects jackfruit growth and development. Therefore, breeding cold-resistant varieties and identifying the vital genes in the process of cold resistance are essential. The dehydration-responsive element binding (DREB) gene family is among the subfamily of the APETALA2/ethylene response factor transcription factor family and is significant in plant abiotic stress responses. METHODS: In this study, a comparative analysis of the cold resistance property of 'GuangXi' ('GX') and 'Thailand' ('THA') jackfruit strains with different cold resistance characteristics was performed through chlorophyll fluorescence and transcriptome sequencing. RESULTS: We found that differentially expressed genes (DEGs) are significantly enriched in the metabolic processes. Here, 93 DREB genes were identified in the jackfruit genome, and phylogenetic analysis was used to classify them into seven groups. Gene structure, conserved motifs, chromosomal location, and homologous relationships were used to analyze the structural characteristics of the DREB family. Transcriptomics indicated that most of the AhDREB genes exhibited down-regulated expression in 'THA.' The DEGs AhDREB12, AhDREB21, AhDREB29, and AhDREB34 were selected for quantitative real-time PCR, and the results showed that these genes also had down-regulated expression in 'THA.' CONCLUSIONS: The above results suggest the significance of the DREB family in improving the cold resistance property of 'GX.'

[Responses of radial growth of Fraxinus mandshurica from different provenances to climate at Maoershan in Northeast China]. / 东北地区帽儿山种源实验林区不同种源水曲柳径向生长对气候的响应.

To understand the responses of radial growth of Fraxinus mandshurica from different provenances to climatic factors, we used the dendrochronological method to establish the standard chronologies of F. mandshurica from 20 provenances in Maoershan provenance test forest, and analyzed the differences in radial growth and their correlation with climate factors. The results showed that the overall trend of F. mandshurica chronologies from 20 provenances was generally similar. There were differences in growth amplitude, with the average radial growth of F. mandshurica from Dailing, Lushuihe and Sanchazi being the highest. The radial growth of F. mandshurica from 20 provenances was significantly positively correlated with the highest temperature in July and the average temperature in July except for Huinan. The radial growth of F. mandshurica from 14 provenances was significantly positively correlated with the precipitation in August. The radial growth of F. mandshurica was constrained by temperature and precipitation during the growing season. There was difference in radial growth among F. mandshurica from different provenances under drought stress. F. mandshurica from Wangqing, Dailing, and Hailin had stronger resistance to drought, while that from Wandianzi, Zhanhe, and Xinglong had better recovery ability after drought.

Gaze Estimation by Attention-Induced Hierarchical Variational Auto-Encoder.

Appearance-based gaze estimation has been widely studied recently with promising performance. The majority of appearance-based gaze estimation methods are developed under the deterministic frameworks. However, the deterministic gaze estimation methods suffer from large performance drop upon challenging eye images in low-resolution, darkness, partial occlusions, etc. To alleviate this problem, in this article, we alternatively reformulate the appearance-based gaze estimation problem under a generative framework. Specifically, we propose a variational inference model, that is, variational gaze estimation network (VGE-Net), to generate multiple gaze maps as complimentary candidates simultaneously supervised by the ground-truth gaze map. To achieve robust estimation, we adaptively fuse the gaze directions predicted on these candidate gaze maps by a regression network through a simple attention mechanism. Experiments on three benchmarks, that is, MPIIGaze, EYEDIAP, and Columbia, demonstrate that our VGE-Net outperforms state-of-the-art gaze estimation methods, especially on challenging cases. Comprehensive ablation studies also validate the effectiveness of our contributions. The code will be publicly released.

MetaKernel: Learning Variational Random Features with Limited Labels.

Few-shot learning deals with the fundamental and challenging problem of learning from a few annotated samples, while being able to generalize well on new tasks. The crux of few-shot learning is to extract prior knowledge from related tasks to enable fast adaptation to a new task with a limited amount of data. In this paper, we propose meta-learning kernels with random Fourier features for few-shot learning, we call MetaKernel. Specically, we propose learning variational random features in a data-driven manner to obtain task-specic kernels by leveraging the shared knowledge provided by related tasks in a meta-learning setting. We treat the random feature basis as the latent variable, which is estimated by variational inference. The shared knowledge from related tasks is incorporated into a context inference of the posterior, which we achieve via a long-short term memory module. To establish more expressive kernels, we deploy conditional normalizing ows based on coupling layers to achieve a richer posterior distribution over random Fourier bases. The resultant kernels are more informative and discriminative, which further improves the few-shot learning. We conduct experiments on both few-shot image classication and regression tasks. The results on fourteen datasets demonstrate MetaKernel consistently better performance than state-of-the-art alternatives.

Variational Abnormal Behavior Detection With Motion Consistency.

Abnormal crowd behavior detection has recently attracted increasing attention due to its wide applications in computer vision research areas. However, it is still an extremely challenging task due to the great variability of abnormal behavior coupled with huge ambiguity and uncertainty of video contents. To tackle these challenges, we propose a new probabilistic framework named variational abnormal behavior detection (VABD), which can detect abnormal crowd behavior in video sequences. We make three major contributions: (1) We develop a new probabilistic latent variable model that combines the strengths of the U-Net and conditional variational auto-encoder, which also are the backbone of our model; (2) We propose a motion loss based on an optical flow network to impose the motion consistency of generated video frames and input video frames; (3) We embed a Wasserstein generative adversarial network at the end of the backbone network to enhance the framework performance. VABD can accurately discriminate abnormal video frames from video sequences. Experimental results on UCSD, CUHK Avenue, IITB-Corridor, and ShanghaiTech datasets show that VABD outperforms the state-of-the-art algorithms on abnormal crowd behavior detection. Without data augmentation, our VABD achieves 72.24% in terms of AUC on IITB-Corridor, which surpasses the state-of-the-art methods by nearly 5%.

Conditional Variational Image Deraining.

Image deraining is an important yet challenging image processing task. Though deterministic image deraining methods are developed with encouraging performance, they are infeasible to learn flexible representations for probabilistic inference and diverse predictions. Besides, rain intensity varies both in spatial locations and across color channels, making this task more difficult. In this paper, we propose a Conditional Variational Image Deraining (CVID) network for better deraining performance, leveraging the exclusive generative ability of Conditional Variational Auto-Encoder (CVAE) on providing diverse predictions for the rainy image. To perform spatially adaptive deraining, we propose a spatial density estimation (SDE) module to estimate a rain density map for each image. Since rain density varies across different color channels, we also propose a channel-wise (CW) deraining scheme. Experiments on synthesized and real-world datasets show that the proposed CVID network achieves much better performance than previous deterministic methods on image deraining. Extensive ablation studies validate the effectiveness of the proposed SDE module and CW scheme in our CVID network. The code is available at https://github.com/Yingjun-Du/VID.

[Telomere Length, Expression of MRE11 and Ku80 in Patients with Aplastic Anemia and Their Correlation with Pathogenesis].

OBJECTIVE: To detect the expression levels of MRE11 and Ku80 mRNA, and telomere length in bone marrow mononuclear cells of aplastic anemia(AA) patients, and to explore their correlation with pathogenesis of aplastic anemia. METHODS: Bone marrow mononuclear cells were collected from 40 cases of AA and 20 normal controls for detecting mRNA expression of MRE11 and Ku80 and telomere length by using real-time quantitative polymerase chain reaction (qPCR), then MRE11, Ku80 and telomere length were analyzed for their correlation. RESULTS: As compared with controls, the expression levels of MRE11 and Ku80 in patients with AA were significantly reduced, and the telomere length in patients with AA was obviously shortened, respectively (P<0. 05). The telomere length was significantly shorter in the persons aged ≥45 years in comparison with the AA patients and normal control younger than 45 years old (P<0.05). For the AA patients older than or equal to 45 years and less than 45 years in comparison with the controls at the same age, the telomere length was significantly shorter(P<0.05). The expression levels of MRE11 and Ku80 didn't correlate with telomere length (P>0.05). The mRNA expression level of MRE11 correlated positively and significantly with that of Ku80 (r=0.863, P<0.05). CONCLUSION: The change of telomere length may play an important role in the pathogenesis and progression of aplastic anemia. The lower expression of MRE11 and Ku80 may be involved in the pathogenesis of aplastic anemia.

[Effects of ultraviolet-C irradiation on membrane lipid peroxidation and activity of PS II electron transport in chloroplasts of Taxus cuspidata needles].

The isolated chloroplasts of Taxus cuspidata needles treated with 12 W.m-2 of ultraviolet-C (UV-C, 254 nm) irradiation were studied under laboratory conditions. The results showed that with the increase of UV-C irradiation, the carotenoids (Car) and glutathione (GSH) contents and superoxide dismutase (SOD) activity were decreased, while the malondialdehyde content (MDA) and the relative permeability of chloroplasts membrane were increased to various extents. The PS II electron transport activity was conspicuous decreased, which had a significant inverse ratio with photosynthetically active radiation (PAR). UV-C irradiation was insensitive on chlorophyll. The results indicated that membrane lipid peroxidation of chloroplasts caused by UV-C radiation was the reason of the decrease of PS II electron transport activity.

[Freezing injury of plant and oxidative stress--superoxide generation in freeze-thaw cycles of cabbage leaf tissues].

To test the hypothesis that oxidative stress is involved in inducing freezing injury of plants, nitroblue tetrazolium (NBT) was infiltrated into cabbage leaf tissues before they were frozen. NBT was reduced to formazans in freeze-thaw cycles. The ethanol-extractable mono-formazan was measured by a spectrophotometer, and used as a quantitative indicator of oxidative stress that developed during a freeze-thaw cycle. NBT per se as an oxidant increased the freezing injury slightly. When Me2SO as a cryoprotectant was infiltrated into leaf tissue, it apparently enhanced the freezing tolerance, and this is correlated to its ability in ameliorating oxidative stress, as indicated by the partial inhibition of NBT reduction. The results supported the hypothesis that freezing injury of plants is related to oxidative stress. The experiments indicated that it was possible that the reductant of NBT in the freeze-thaw cycle was superoxide anion free radical.