Genome-wide identification of drought-responsive microRNAs and their target genes in Chinese jujube by deep sequencing.

BACKGROUND: MicroRNAs (miRNAs) are about 21 snucleotide (nt) long, non-coding RNAs that play an important role in plant abiotic stress responses. Chinese jujube is a native fruit tree in China, which is also an admittedly drought-resistant plant. But the drought-related miRNAs have little been reported in jujube. OBJECTIVE: To identify possibly drought-responsive microRNAs and their target genes in Chinese Jujube. METHODS: Twelve small RNA libraries were constructed from two jujube genotypes both drought treated and control samples with three replicates to identify known and novel miRNAs in Chinese Jujube, DESeq2 was used to identify expression pattern of miRNAs between drought treatment and control samples, TargetFinder program was used to predict potential target genes of conserved and novel miRNAs, RT-qPCR were used to analysis the expression levels of drought-related miRNAs and their potential targets. The RNA ligase-mediated RLM-5' RACE experiments were performed to validate predicted target genes of drought-related miRNAs. RESULTS: 43 known miRNAs and 431 novel miRNAs were identified in Chinese jujube. Expression analysis showed that 28 miRNAs were differential expressed under drought stress in jujube variety "Dongzao", including 21 up-regulated miRNAs and 7 down-regulated miRNAs, 61 miRNAs were differential expressed under drought stress in Chinese jujube variety "Zanhuangdazao", including 23 up-regulated miRNAs and 37 down-regulated miRNAs. Depend on miRNAs target prediction, functional annotation and expression analysis, we identified 9 drought-related miRNAs, and 7 target genes of 6 miRNAs were confirmed using the modified 5'-RACE method. Also, RT-qPCR analyses revealed that relative expression of those miRNAs and their targets have negative tendency. CONCLUSION: We identified 6 drought-related miRNAs by high-throughout sequencing and target gene annotation from Chinese jujube, and targets of those miRNAs were confirmed by the modified 5'-RACE method. These findings provide molecular evidence for enhancing drought tolerance in Chinese jujube and other plants.

Stu-miR827-Targeted StWRKY48 Transcription Factor Negatively Regulates Drought Tolerance of Potato by Increasing Leaf Stomatal Density.

Stomata are specialized portals in plant leaves to modulate water loss from plants to the atmosphere by control of the transpiration, thereby determining the water-use efficiency and drought resistance of plants. Despite that the stomata developmental progression is well-understood at the molecular level, the experimental evidence that miRNA regulates stomata development is still lacking, and the underlying mechanism remains elusive. This study demonstrates the involvement of stu-miR827 in regulating the drought tolerance of potato due to its control over the leaf stomatal density. The expression analysis showed that stu-miR827 was obviously repressed by drought stresses and then rapidly increased after rewatering. Suppressing the expression of stu-miR827 transgenic potato lines showed an increase in stomatal density, correlating with a weaker drought resistance compared with wildtype potato lines. In addition, StWRKY48 was identified as the target gene of stu-miR827, and the expression of StWRKY48 was obviously induced by drought stresses and was greatly upregulated in stu-miR827 knockdown transgenic potato lines, suggesting its involvement in the drought stress response. Importantly, the expression of genes associated with stomata development, such as SDD (stomatal density and distribution) and TMM (too many mouths), was seriously suppressed in transgenic lines. Altogether, these observations demonstrated that suppression of stu-miR827 might lead to overexpression of StWRKY48, which may contribute to negatively regulating the drought adaptation of potato by increasing the stomatal density. The results may facilitate functional studies of miRNAs in the process of drought tolerance in plants.

Oscillatory self-organization dynamics between soliton molecules induced by gain fluctuation.

In passively mode-locked fiber lasers (PMLFLs), the dissipative solitons (DSs) can self-organize to form complex structures through delicate interactions. However, it is still elusive to control these soliton structures by external influences. We here find that at a certain critical power, the location between two soliton molecules can be controlled by a slow modulated pump power. After applying the pump power with periodic fluctuation, two soliton molecules oscillate from the state of soliton molecular complex to stable distribution with maximum inter-molecular separation. During this process, the internal structure of each soliton molecule keeps steady. The slow gain depletion and recovery mechanism which plays a dominant role affects the motion of soliton molecules. These results could further expand the molecular analogy of spectroscopy and stimulate the development of optical information storage and processing.

Cardiac manifestations of Han Chinese patients with systemic lupus erythematosus: a retrospective study.

OBJECTIVE: To investigate cardiac manifestations and the risk factors in Han Chinese patients with systemic lupus erythematosus (SLE). METHODS: Seven hundred fifty SLE patients who were hospitalized at our department were recruited in the present study. The patients were divided into two groups-those with or without cardiac manifestations. Cardiac manifestations in those SLE patients, such as pericarditis, myocarditis, heart valve disease, arrhythmia, were analyzed. The risk and protective factors of cardiac diseases in patients with SLE, as well as the predictors of mortality, were assessed, respectively. RESULTS: In all 750 SLE patients, there were 339 (45.20%) patients suffered from one or more cardiac manifestations, involving pericarditis in 9.5%, myocarditis in 5.7%, heart valve disease in 15.6%, arrhythmia in 16.67%, and cardiovascular diseases (CVD) in 14%. 15.7% of SLE patients were accompanied with pulmonary arterial hypertension (PAH), of which 13.7% were mild, 1.2% were moderate, and 0.8% were severe. No significant differences were found between the two groups in age, disease duration, gender, antibody, and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). The incidence of pericarditis, heart valve disease, arrhythmia, and PAH was positively correlated with age. The incidence of arrhythmia, CVD, and PAH was correlated with SLEDAI. PAH and myocarditis were the risk factors of mortality in SLE patients with disease duration ≤ 10 years (P = 0.034 and 0.001, respectively). CONCLUSION: Cardiac involvement is common in Han Chinese SLE patients and associated with age and disease activity. PAH and myocarditis are the risk factors of mortality in SLE.