Plant salt-stress response involves complex physiological processes. Previous studies have shown that some factors promote salt tolerance only under high transpiring condition, thus mediating ...transpiration-dependent salt tolerance (TDST). However, the mechanism underlying crop TDST remains largely unknown. Here, we report that ZmSTL1 (Salt-Tolerant Locus 1) confers natural variation of TDST in maize. ZmSTL1 encodes a dirigent protein (termed ZmESBL) localized to the Casparian strip (CS) domain. Mutants lacking ZmESBL display impaired lignin deposition at endodermal CS domain which leads to a defective CS barrier. Under salt condition, mutation of ZmESBL increases the apoplastic transport of Na
across the endodermis, and then increases the root-to-shoot delivery of Na
via transpiration flow, thereby leading to a transpiration-dependent salt hypersensitivity. Moreover, we show that the ortholog of ZmESBL also mediates CS development and TDST in Arabidopsis. Our study suggests that modification of CS barrier may provide an approach for developing salt-tolerant crops.
Abstract
Sodium (Na
+
) toxicity is one of the major damages imposed on crops by saline-alkaline stress. Here we show that natural maize inbred lines display substantial variations in shoot Na
+
...contents and saline-alkaline (NaHCO
3
) tolerance, and reveal that
ZmNSA1
(
Na
+
Content under Saline-Alkaline Condition
) confers shoot Na
+
variations under NaHCO
3
condition by a genome-wide association study. Lacking of ZmNSA1 promotes shoot Na
+
homeostasis by increasing root Na
+
efflux. A naturally occurred 4-bp deletion decreases the translation efficiency of
ZmNSA1
mRNA, thus promotes Na
+
homeostasis. We further show that, under saline-alkaline condition, Ca
2+
binds to the EF-hand domain of ZmNSA1 then triggers its degradation via 26S proteasome, which in turn increases the transcripts levels of PM-H
+
-ATPases (
MHA2
and
MHA4
), and consequently enhances SOS1 Na
+
/H
+
antiporter-mediated root Na
+
efflux. Our studies reveal the mechanism of Ca
2+
-triggered saline-alkaline tolerance and provide an important gene target for breeding saline-alkaline tolerant maize varieties.
Aims
Drawing on the conservation of resources theory, this study examines the underlying process through which servant leadership is associated with nurses' in‐role performance. Specifically, we test ...the indirect effect of servant leadership on in‐role performance via a sequential mediating mechanism of job autonomy and emotional exhaustion.
Design
A time‐lagged design was implemented using data gathered from two‐wave online surveys (1 week apart) of registered nurses from Jiangsu Province, China.
Methods
Between September 2022 and February 2023, we used Wenjuanxing and Credma, which are two powerful and user‐friendly data collection platforms, to distribute online surveys to potential participants. We received a total of 220 usable responses and employed the PROCESS Model 4 and Model 6 to assess our proposed hypotheses.
Results
Our proposed model was supported. Servant leadership has a positive indirect effect on nurses' in‐role performance through job autonomy and emotional exhaustion. Job autonomy has a negative effect on emotional exhaustion. Additionally, job autonomy mediates the negative relationship between servant leadership and emotional exhaustion.
Conclusion
The present research extends existing nursing studies by unravelling the complex mechanisms underlying the relationship between servant leadership and nurses' in‐role performance. Our study also identifies the underlying mechanism of how servant leadership mitigates emotional exhaustion by supporting nurses' job autonomy.
Impact
The sequential mediation results provide us with a more fine‐grained understanding of the relationship between servant leadership and nurses' in‐role performance. It further promotes job autonomy and decreases emotional exhaustion, which supports the UN Sustainable Development Goal #3 (Good Health and Well‐being).
Patient or Public Contribution
This study addresses the UN Sustainable Development Goal #3: ‘To ensure healthy lives and promote well‐being for all at all ages’ and the healthcare providers will benefit from our study. Therefore, the study contributes to a more sustainable organization and society.
Exosomes are nanosized membrane vesicles released from cells after fusion of multivesicular bodies (MVBs) with the plasma membrane (PM) and play important roles in intercellular communication and ...numerous biological processes. However, the molecular mechanisms regulating exosome secretion remain poorly understood. Here we identify KIBRA as an adaptor-like protein that stabilizes Rab27a, which in turn controls exosome secretion both in vitro and in vivo. Knockdown or overexpression of KIBRA in neuronal and podocyte cell lines leads to a decrease or increase of exosome secretion, respectively, and KIBRA depletion increases MVB size and number. Comparing protein profiles between KIBRA knockout and wild-type mouse brain showed significantly decreased Rab27a, a small GTPase that regulates MVB-PM docking. Rab27a is stabilized by interacting with KIBRA, which prevents ubiquitination and degradation via the ubiquitin-proteasome pathway. In conclusion, we show that KIBRA controls exosome secretion via inhibiting the proteasomal degradation of Rab27a.
• Maize was domesticated from Balsas teosinte c. 10 000 yr ago. Previous studies have suggested that increased tolerance to environmental stress occurred during maize domestication. However, the ...underlying genetic basis remains largely unknown.
• We used a maize (W22)–teosinte recombinant inbred line (RIL) to investigate the salt wild-type tolerance aspects of maize domestication.
• We revealed that ZmHKT2 is a major QTL that regulates K⁺ homeostasis in saline soils. ZmHKT2 encodes a K⁺-preferring HKT family transporter and probably reduces shoot K⁺ content by removing K⁺ ions from root-to-shoot flowing xylem sap, ZmHKT2 deficiency increases xylem sap and shoot K⁺ concentrations, and increases salt tolerance. A coding sequence polymorphism in the ZmHKT2W22
allele (SNP389-G) confers an amino acid variant ZmHKT2 that increases xylem sap K⁺ concentration, thereby increasing shoot K⁺ content and salt tolerance. Additional analyses showed that SNP389-G first existed in teosinte (allele frequency 56% in assayed accessions), then swept through the maize population (allele frequency 98%), and that SNP389-G probably underwent positive selection during maize domestication.
• We conclude that a domestication-associated reduction in K⁺ transport activity in ZmHKT2 underlies maize shoot K⁺ content and salt tolerance, and propose that CRISPR-based editing of ZmHKT2 might provide a feasible strategy for improving maize salt tolerance.
Summary
Sodium (Na+) is the major cation damaging crops in the salinised farmland. Previous studies have shown that the Salt Overly Sensitive (SOS) pathway is important for salt tolerance in ...Arabidopsis. Nevertheless, the SOS pathway remains poorly investigated in most crops.
This study addresses the function of the SOS pathway and its association with the natural variation of salt tolerance in maize.
First, we showed that a naturally occurring 4‐bp frame‐shifting deletion in ZmSOS1 caused the salt hypersensitive phenotype of the maize inbred line LH65. Accordingly, mutants lacking ZmSOS1 also displayed a salt hypersensitive phenotype, due to an impaired root‐to‐rhizosphere Na+ efflux and an increased shoot Na+ concentration. We next showed that the maize SOS3/SOS2 complex (ZmCBL4/ZmCIPK24a and ZmCBL8/ZmCIPK24a) phosphorylates ZmSOS1 therefore activating its Na+‐transporting activity, with their loss‐of‐function mutants displaying salt hypersensitive phenotypes. Moreover, we observed that a LTR/Gypsy insertion decreased the expression of ZmCBL8, thereby increasing shoot Na+ concentration in natural maize population.
Taken together, our study demonstrated that the maize SOS pathway confers a conservative salt‐tolerant role, and the components of SOS pathway (ZmSOS1 and ZmCBL8) confer the natural variations of Na+ regulation and salt tolerance in maize, therefore providing important gene targets for breeding salt‐tolerant maize.
See also the Commentary on this article by Arciniegas Vega & Melino, 236: 313–315.
In this randomized trial involving infertile women with the polycystic ovary syndrome, frozen-embryo transfer was associated with a higher rate of live birth than was fresh-embryo transfer after the ...first transfer.
In vitro fertilization (IVF) is widely performed as an infertility treatment and has resulted in the births of more than 5 million infants worldwide.
1
However, there are concerns about the safety of the procedures for women and for their infants.
1
,
2
The ovarian hyperstimulation syndrome (which is caused by ovarian enlargement, an increase in vascular permeability and abdominal ascites, and intravascular hemoconcentration) is a potentially life-threatening complication of ovarian stimulation.
3
Pregnancies conceived by means of IVF are associated with greater risks of maternal and neonatal complications, including preeclampsia, preterm delivery, low birth weight, and congenital anomalies, than are spontaneous pregnancies. . . .
Soil salinity is one of several major abiotic stresses that constrain maize productivity worldwide. An improved understanding of salt-tolerance mechanisms will thus enhance the breeding of ...salt-tolerant maize and boost productivity. Previous studies have indicated that the maintenance of leaf Na+ concentration is essential for maize salt tolerance, and the difference in leaf Na+ exclusion has previously been associated with variation in salt tolerance between maize varieties.
Here, we report the identification and functional characterization of a maize salt-tolerance quantitative trait locus (QTL), Zea mays Na
+
Content1 (ZmNC1), which encodes an HKT-type transporter (designated as ZmHKT1).
We show that a natural ZmHKT1 loss-of-function allele containing a retrotransposon insertion confers increased accumulation of Na+ in leaves, and salt hypersensitivity. We next show that ZmHKT1 encodes a plasma membrane-localized Na+-selective transporter, and is preferentially expressed in root stele (including the parenchyma cells surrounding the xylem vessels). We also show that loss of ZmHKT1 function increases xylem sap Na+ concentration and causes increased root-to-shoot Na+ delivery, indicating that ZmHKT1 promotes leaf Na+ exclusion and salt tolerance by withdrawing Na+ from the xylem sap.
We conclude that ZmHKT1 is a major salt-tolerance QTL and identifies an important new gene target in breeding for improved maize salt tolerance.
Objective To determine whether the high lipid content of human follicular fluid influences oocyte maturation. Design Mouse oocytes as substitutes for human oocytes were exposed to follicular fluids ...of differing lipid content with outcome monitoring. Setting Private infertility clinic and university laboratory. Patient(s) Seventy-four women seeking assisted reproduction, and gonadotropin-stimulated mice. Intervention(s) Assay of follicular fluids for triglyceride and free fatty acids, and stimulation of mouse cumulus-oocyte complexes (COCs) to maturity in vitro in the presence of lipid-rich or lipid-poor follicular fluid. Main Outcome Measure(s) Oocyte lipid content, expression of endoplasmic reticulum stress marker genes, and oocyte maturation assessed in mouse COCs exposed to lipid-rich follicular fluid were compared with complexes exposed to lipid-poor follicular fluid and complexes matured in vivo. Result(s) Follicular fluids were obtained from women of known body mass index undergoing oocyte aspiration at a private infertility clinic, and the follicular fluids were assayed for triglyceride and free fatty acids; those with the highest and lowest levels of these lipids were selected. The mouse COCs exposed to lipid-rich follicular fluid during their maturation had increased oocyte lipid content, induction of endoplasmic reticulum stress markers, and impaired oocyte nuclear maturation. Conclusion(s) Increased body mass index is associated with elevated triglycerides and free fatty acids in ovarian follicular fluid. Maturation within this lipid-rich environment is detrimental to oocytes.
In this study, we numerically simulate the evolution of the orbital angular momentum (OAM) spectrum of a vortex laser beam in the optical parametric chirped pulse amplification (OPCPA) process, which ...is an effective technical method to realize ultra-intense and ultra-short vortex laser amplification. The results show that the proportion of the vortex laser beam with 100% topological charge (TC) of 1 decreases to 97.44% with the enhancement of the saturation amplification after amplification by a 15 mm length LBO pumped by a 526.5 nm laser with a pump intensity of 1.74 GW/cm
. Conversely, the beams with other topological charges generate and increase with the amplification. The simulation results are consistent with our previous experimental results. Meanwhile, compared with non-collinear OPCPA, collinear OPCPA can maintain well the proportion of TC Formula: see text.
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