Nitrate transporters are primarily responsible for absorption of nitrate from soil and nitrate translocation among different parts of plants. They deliver nitrate to where it is needed. However, ...recent studies have revealed that nitrate transporters are extensively involved in coping with adverse environmental conditions besides limited nitrate/nitrogen availability. In this review, we describe the functions of the nitrate transporters related to abiotic stresses and their regulation. The expected and unexpected roles of nitrate transporters in plant abiotic stress resistance will also be discussed.
Light, temperature, water, and fertilizer are arguably the most important environmental factors regulating crop growth and productivity. Environmental stimuli, including low light, extreme ...temperatures, and water stresses caused by climate change, affect crop growth and production and pose a growing threat to sustainable agriculture. Furthermore, soil salinity is another major environmental constraint affecting crop growth and threatening global food security. The grain filling stage is the final stage of growth and is also the most important stage in cereals, directly determining the grain weight and final yield. However, the grain filling process is extremely vulnerable to different environmental stimuli, especially for inferior spikelets. Given the importance of grain filling in cereals and the deterioration of environmental problems, understanding environmental stimuli and their effects on grain filling constitutes a major focus of crop research. In recent years, significant advances made in this field have led to a good description of the intricate mechanisms by which different environmental stimuli regulate grain filling, as well as approaches to adapt cereals to changing climate conditions and to give them better grain filling. In this review, the current environmental stimuli, their dose-response effect on grain filling, and the physiological and molecular mechanisms involved are discussed. Furthermore, what we can do to help cereal crops adapt to environmental stimuli is elaborated. Overall, we call for future research to delve deeper into the gene function-related research and the commercialization of gene-edited crops. Meanwhile, smart agriculture is the development trend of the future agriculture under environmental stimuli.
Poor grain filling of inferior spikelets, especially in some large-panicle rice varieties, is becoming a major limitation in breaking the ceiling of rice production. In our previous studies, we ...proved that post-anthesis moderate soil drying (MD) was an effective way to promote starch synthesis and inferior grain filling. As one of the most important regulatory processes in response to environmental cues and at different developmental stages, the function of alternative splicing (AS) has not yet been revealed in regulating grain filling under MD conditions. In this study, AS events at the most active grain-filling stage were identified in inferior spikelets under well-watered control (CK) and MD treatments. Of 16,089 AS events, 1840 AS events involving 1392 genes occurred differentially between the CK and MD treatments, many of which function on spliceosome, ncRNA metabolic process, starch, and sucrose metabolism, and other functions. Some of the splicing factors and starch synthesis-related genes, such as SR protein, hnRNP protein, OsAGPL2, OsAPS2, OsSSIVa, OsSSIVb, OsGBSSII, and OsISA1 showed differential AS changes under MD treatment. The expression of miR439f and miR444b was reduced due to an AS event which occurred in the intron where miRNAs were located in the MD-treated inferior spikelets. On the contrary, OsAGPL2, an AGPase encoding gene, was alternatively spliced, resulting in different transcripts with or without the miR393b binding site, suggesting a potential mechanism for miRNA-mediated gene regulation on grain filling of inferior spikelets in response to MD treatment. This study provides some new insights into the function of AS on the MD-promoted grain filling of inferior spikelets, and potential application in agriculture to increase rice yields by genetic approaches.
Metastasis is the most prevalent cause of cancer-associated deaths amongst patients with cervical cancer. Epithelial-mesenchymal transition (EMT) is essential for carcinogenesis, and it confers ...metastatic properties to cancer cells. Gossypol is a natural polyphenolic compound with anti-inflammation, anti-oxidant, and anticancer activities. In this study, we investigated the antimetastatic and antitumour effects of gossypol on human cervical cancer cells (HeLa and SiHa cells). Gossypol exerted a strong inhibition effect on the migration and invasion of human cervical cancer cells. It reduced the focal adhesion kinase (FAK) pathway-mediated expression of matrix metalloproteinase-2 and urokinase-type plasminogen activator, subsequently inhibiting the invasion of SiHa cells. In addition, gossypol reversed EMT induced by transforming growth factor beta 1 (TGF-Formula: see text1) and up-regulated epithelial markers, such as E-cadherin but significantly suppressed Ras homolog family member (Rho)A, RhoB, and p-Samd3. The tail vein injection model showed that gossypol treatment via oral gavage reduced lung metastasis. Gossypol also decreased tumour growth
in the nude mouse xenograft model. All these findings suggest that gossypol suppressed the invasion and migration of human cervical cancer cells by targeting the FAK signaling pathway and reversing TGF-Formula: see text1-induced EMT. Hence, gossypol warrants further attention for basic mechanistic studies and drug development.
Nitrogen deficiency induces leaf senescence. However, whether or how nitrate might affect this process remains to be investigated. Here, we report an interesting finding that nitrate-- instead of ...nitrogen--starvation induced early leaf senescence in nrtf.5 mutant, and present genetic and physiological data demon-strating that nitrate starvation-induced leaf senescence is suppressed by NRTI.5. NRT1.5 suppresses the senescence process dependent on its function from roots, but not the nitrate transport function. Further analyses using nrt1.5 single and nial nia2 nrt1.5-4 triple mutant showed a negative correlation between nitrate concentration and senescence rate in leaves. Moreover, when exposed to nitrate starvation, foliar potassium level decreased in nrt1.5, but adding potassium could essentially restore the early leaf senescence phenotype of nrt1.5 plants. Nitrate starvation also downregulated the expression of HAK5, RAP2.11, and ANN1 in nrt1.5 roots, and appeared to alter potassium level in xylem sap from nrt1.5. These data suggest that NRT1.5 likely perceives nitrate starvation-derived signals to prevent leaf senescence by facilitating foliar potassium accumulation.
Hyperaccumulator plants are ideal models for investigating the regulatory mechanisms of plant metal homeostasis and environmental adaptation due to their notable traits of metal accumulation and ...tolerance. These traits may benefit either the biofortification of essential mineral nutrients or the phytoremediation of nonessential toxic metals. A common mechanism by which elevated expression of key genes involved in metal transport or chelation contributes to hyperaccumulation and hypertolerance was proposed mainly from studies examining two Brassicaceae hyperaccumulators, namely
Arabidopsis halleri
and
Noccaea caerulescens
(formerly
Thlaspi caerulescens
). Meanwhile, recent findings regarding systems outside the Brassicaceae hyperaccumulators indicated that functional enhancement of key genes might represent a strategy evolved by hyperaccumulator plants. This review provides a brief outline of metal hyperaccumulation in plants and highlights commonalities and differences among various hyperaccumulators.
This paper proposes a digital background calibration scheme for calibrating the linear and the third-order nonlinear gain errors of the residue amplifiers (RAs) in pipelined ADCs. It is based on a ...novel multiple-correlation estimation (MCE) technique. We define two correction parameters relating to the gain errors of the RA under calibration. By alternately injecting two bi-level pseudo-random signals with designated amplitudes to the RA through the sub-DAC, the desired correction parameters are estimated according to the correlations of the backend ADC's outputs and the injected pseudo-random signals. Two least-mean-square (LMS) loops are adopted to find and to track the optimal values of the correction parameters. Simulation results of a 12-bit pipelined ADC show that the SNDR is improved from 46.4 dB to 73.4 dB with the help of the proposed calibration design. The proposed calibration scheme has the advantages of simple implementation, no restriction on the input signal of the ADC, fast settling, and running in background.
Glycolate oxidase (GLO) is a key enzyme for photorespiration in plants. There are four GLO genes encoding and forming different isozymes in rice, but their functional differences are not well ...understood. In this study, enzymatic and physiological characteristics of the GLO isozymes were comparatively analyzed.
When expressed heterologously in yeast, GLO1, GLO4 and GLO1 + 4 showed the highest activities and lowest K
for glycolate as substrate, whereas GLO3 displayed high activities and affinities for both glycolate and L-lactate, and GLO5 was catalytically inactive with all substrates tested. To further reveal the physiological role of each GLO isozyme in plants, various GLO genetically modified rice lines were generated and functionally analyzed. GLO activity was significantly increased both in GLO1 and GLO4 overexpression lines. Nevertheless, when either GLO1 or GLO4 was knocked out, the activity was suppressed much more significantly in GLO1 knockout lines than in GLO4 knockout lines, and both knockout mutants exhibited obvious dwarfism phenotypes. Among GLO3 and GLO5 overexpression lines and RNAi lines, only GLO3 overexpression lines showed significantly increased L-lactate-oxidizing activity but no other noticeable phenotype changes.
These results indicate that rice GLO isozymes have distinct enzymatic characteristics, and they may have different physiological functions in rice.
AIM:To evaluate total embolization of the main splenic artery in patients with splenic artery aneurysms(SAAs)and normal spleen.METHODS:Thirty-five consecutive patients with SAAs were referred for ...treatment with coil embolization.Patients were classified into two groups:coil embolization of the main splenic artery with complete occlusion of the artery and aneurysms(group A,n=16),and coil embolization of the aneurysmal sac with patency of the splenic artery(group B,n=19).Data on white blood cell(WBC)and platelet counts,liver function,and complications were collected on days 7 and 30,and subsequently at a 6-mo interval postoperatively.Abdominal computed tomography was routinely performed to calculate the splenic volume before and 1 mo after the procedure,and subsequently every 6 mo during follow-up.RESULTS:Coil embolization of the SAAs was technically successful in all 35 patients,with no procedurerelated complications.The post-embolization syndrome,including abdominal pain,fever and vomiting,occurred in six patients(37.5%)in group A and three patients in group B(15.8%).There were no significant differences in WBC and platelet counts between preoperatively and at each follow-up point after the procedures.There were also no significant differences in average WBC and platelet counts between the two groups at each follow-up point.There were significant differences in splenic volume in group A between preoperatively and at each follow-up point,and there were also significant differences in splenic volume between the two groups at each follow-up point.CONCLUSION:Total embolization of the main splenic artery was a safe and feasible procedure for patients with SAAs and normal spleen.
Real-world vaccine effectiveness following the third dose of vaccination against SARS-CoV-2 remains less investigated among people with HIV (PWH).
PWH receiving the third dose of BNT162b2 and ...mRNA-1273 (either 50- or 100-μg) were enrolled. Participants were followed for 180 days until the fourth dose of COVID-19 vaccination, SARS-CoV-2 infection, seroconversion of anti-nucleocapsid IgG, death, or loss to follow-up. Anti-spike IgG was determined every 1–3 months.
Of 1427 participants undergoing the third-dose COVID-19 vaccination, 632 (44.3%) received 100-μg mRNA-1273, 467 (32.8%) 50-μg mRNA-1273, and 328 (23.0%) BNT162b2 vaccine and the respective rate of SARS-CoV-2 infection or seroconversion of anti-nucleocapsid IgG was 246.1, 280.8 and 245.2 per 1000 person-months of follow-up (log-rank test, p = 0.28). Factors associated with achieving anti-S IgG titers >1047 BAU/mL included CD4 count <200 cells/mm3 (adjusted odds ratio aOR, 0.11; 95% CI, 0.04–0.31), plasma HIV RNA >200 copies/mL (aOR, 0.27; 95% CI, 0.09–0.80), having achieved anti-spike IgG >141 BAU/mL within 3 months after primary vaccination (aOR, 3.69; 95% CI, 2.68–5.07), receiving BNT162b2 vaccine as the third dose (aOR, 0.20; 95% CI, 0.10–0.41; reference, 100-μg mRNA-1273), and having previously received two doses of mRNA vaccine in primary vaccination (aOR, 2.46; 95% CI, 1,75-3.45; reference, no exposure to mRNA vaccine).
PWH receiving different types of the third dose of COVID-19 vaccine showed similar vaccine effectiveness against SARS-CoV-2 infection. An additional dose with 100-μg mRNA-1273 could generate a higher antibody response than with 50-μg mRNA-1273 and BNT162b2 vaccine.
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