PAMP-INDUCED SECRETED PEPTIDE 3 modulates salt tolerance through RECEPTOR-LIKE KINASE 7 in plants.

High soil salinity negatively affects plant growth and development, leading to a severe decrease in crop production worldwide. Here, we report that a secreted peptide, PAMP-INDUCED SECRETED PEPTIDE 3 (PIP3), plays an essential role in plant salt tolerance through RECEPTOR-LIKE KINASE 7 (RLK7) in Arabidopsis (Arabidopsis thaliana). The gene encoding the PIP3 precursor, prePIP3, was significantly induced by salt stress. Plants overexpressing prePIP3 exhibited enhanced salt tolerance, whereas a prePIP3 knockout mutant had a salt-sensitive phenotype. PIP3 physically interacted with RLK7, a leucine-rich repeat RLK, and salt stress enhanced PIP3-RLK7 complex formation. Functional analyses revealed that PIP3-mediated salt tolerance is dependent on RLK7. Exogenous application of synthetic PIP3 peptide activated RLK7, and salt treatment significantly induced RLK7 phosphorylation in a PIP3-dependent manner. Notably, MITOGEN-ACTIVATED PROTEIN KINASE3 (MPK3) and MPK6 were downstream of the PIP3-RLK7 module in salt response signaling. Activation of MPK3/6 was attenuated in pip3 or rlk7 mutants under saline conditions. Therefore, MPK3/6 might amplify salt stress response signaling in plants for salt tolerance. Collectively, our work characterized a novel ligand-receptor signaling cascade that modulates plant salt tolerance in Arabidopsis. This study contributes to our understanding of how plants respond to salt stress.

MYB30 Regulates Submergence Tolerance by Repressing Ethylene Biosynthesis via ACS7 in Arabidopsis.

Floods impose detrimental effects on natural and agro-ecosystems, leading to a significant loss of worldwide crop production. Global climate change has even worsened this situation. Flooding is a continuous process including two stages of submergence and re-oxygenation, and both are harmful to plant growth and development, resulting in a serious decline in crop yield. Therefore, the understanding of plant flooding tolerance and developing flooding-resistant crops are of great significance. Here, we report that the Arabidopsis thaliana (Arabidopsis) R2R3-MYB transcription factor MYB30 participates in plant submergence response through 1-aminocyclopropane-1-carboxylic acid synthase 7 (ACS7) by repressing ethylene (ET) biosynthesis. The MYB30 loss-of-function mutant exhibits reduced submergence tolerance with a higher level of ET production, whereas the MYB30-overexpressing plant displays enhanced submergence tolerance and repressed ET production. The coding gene of ACS7 might be a direct target of MYB30 during the submergence response. MYB30 binds to the promoter of ACS7 and represses its transcription. The ACS7 loss-of-function mutant with defect in ET biosynthesis displays enhanced submergence tolerance, whereas plants overexpressing ACS7 exhibit a submergence-sensitive phenotype. Genetic analysis shows that ACS7 functions downstream of MYB30 in both ET biosynthesis and submergence response. Taken together, our work revealed a novel transcriptional regulation that modulates submergence response in plants.

SUMOylation of MYB30 enhances salt tolerance by elevating alternative respiration via transcriptionally upregulating AOX1a in Arabidopsis.

Salt stress reduces crop growth and productivity globally. Here we report that a R2R3-MYB transcription factor MYB30 participates in salt tolerance in Arabidopsis. MYB30 can be SUMOylated by SIZ1 in response to salt stress and the lysine (K)283 of MYB30 is essential for its SUMOylation. In contrast to wild-type MYB30, the MYB30K283R mutant failed to rescue the salt-sensitive phenotype of the myb30-2 mutant, indicating that SUMOylation of MYB30 is required for the salt-stress response. Through transcriptomic analysis, we identified a MYB30 target, alternative oxidase 1a (AOX1a). MYB30 binds the promoter of AOX1a and upregulates its expression in response to salt stress; however, MYB30K283R cannot bind the promoter of AOX1a. The cyanide (CN)-resistant alternative respiration (Alt) mediated by AOX is significantly reduced in the myb30-2 mutant through the loss of function of MYB30. As a result, the redox homeostasis is disrupted in the myb30-2 mutant compared with that in wild-type seedlings (WT) under salt conditions. The artificial elimination of excess reactive oxygen species partially rescues the salt-sensitive phenotype of the myb30-2 mutant, whereas after the exogenous application of SHAM, an inhibitor of AOXs and Alt respiration, the salt tolerance of Col-0 and the complemented plants decreased to a level similar to that observed in myb30-2. Finally, overexpression of AOX1a in myb30-2 confers WT-like salt tolerance compared with that of the myb30-2 mutant. Taken together, our results revealed a functional link between MYB30 and AOX1a, and indicated that SIZ1-mediated SUMOylation of MYB30 enhances salt tolerance by regulating Alt respiration and cellular redox homeostasis via AOX1a in Arabidopsis.

SIMP1 modulates salt tolerance by elevating ERAD efficiency through UMP1A-mediated proteasome maturation in plants.

Salt stress significantly induces accumulation of misfolded or unfolded proteins in plants. Endoplasmic reticulum (ER)-associated protein degradation (ERAD) and other degradative machineries function in the degradation of these abnormal proteins, leading to enhanced salt tolerance in plants. Here we characterise that a novel receptor-like kinase, Salt-Induced Malectin-like domain-containing Protein1 (SIMP1), elevates ERAD efficiency during salt stress through UMP1A, a putative proteasome maturation factor in Arabidopsis. SIMP1 loss-of-function caused a salt-hypersensitive phenotype. SIMP1 interacts and phosphorylates UMP1A, and the protein stability of UMP1A is positively regulated by SIMP1. SIMP1 modulates the 26S proteasome maturation possibly through enhancing the recruitment of specific ß subunits of the core catalytic particle to UMP1A. Functionally, the SIMP1-UMP1A module plays a positive role in ERAD efficiency in Arabidopsis. The degradation of misfolded/unfolded proteins was impaired in both simp1 and ump1a mutants during salt stress. Consistently, both simp1 and ump1a plants exhibited reduced ER stress tolerance. Phenotypic analysis revealed that SIMP1 regulates salt tolerance through UMP1A at least in part. Taken together, our work demonstrated that SIMP1 modulates plant salt tolerance by promoting proteasome maturation via UMP1A, therefore mitigating ER stress through enhanced ERAD efficiency under saline conditions.

Transcriptome analysis of Hevea brasiliensis in response to exogenous methyl jasmonate provides novel insights into regulation of jasmonate-elicited rubber biosynthesis.

The phytohomorne methyl jasmonate (MeJA) is known to trigger extensive reprogramming of gene expression leading to transcriptional activation of many secondary metabolic pathways. However, natural rubber is a commercially important secondary metabolite and little is known about the genetic and genomic basis of jasmonate-elicited rubber biosynthesis in rubber tree (Hevea brasiliensis). RNA sequencing (RNA-seq) of H. brasiliensis bark treated with 1 g lanolin paste containing 0.02% w/w MeJA for 24 h (M2) and 0.04% w/w MeJA for 24 h (M4) was performed. A total of 2950 and 2850 differentially expressed genes in M2 and M4 compared with control (C) were respectively detected. Key genes involved in 2-C-methyl-D-erythritol 4-phosphate, rubber biosynthesis, glycolysis and carbon fixation (Calvin cycle) pathway were found to be up-regulated by MeJA treatment. Particularly, the expression of 3-hydroxy-3-metylglutaryl coenzyme A reductase in MVA pathway was down-regulated by MeJA treatment, but the expression of farnesyl diphosphate synthase (FPS) and cis-prenyltransferase (CPT, or rubber transferase) in rubber biosynthesis pathway were up-regulated by MeJA treatment. Up-regulation of critical genes in JA biosynthesis in response to MeJA treatment exhibited the self-activation of JA biosynthesis. In addition, up-regulated genes of great regulatory importance in cross-talk between JA and other hormone signaling, and of transcriptional regulation were identified. The increased expression levels of FPS and CPT in rubber biosynthesis pathway possibly resulted in an increased latex production in rubber tree treated with MeJA. The present results provide insights into the mechanism by which MeJA activates the rubber biosynthesis and the transcriptome data can also serve as the foundation for future research into the molecular basis for MeJA regulation of other cellular processes.

Molecular mechanism of ethylene stimulation of latex yield in rubber tree (Hevea brasiliensis) revealed by de novo sequencing and transcriptome analysis.

BACKGROUND: Rubber tree (Hevea brasiliensis) is an important industrial crop cultivated in tropical areas for natural rubber production. Treatment of the bark of rubber trees with ehephon (an ethylene releaser) has been a routine measure to increase latex yield, but the molecular mechanism behind the stimulation of rubber production by ethylene still remains a puzzle. Deciphering the enigma is of great importance for improvement of rubber tree for high yield. RESULTS: De novo sequencing and assembly of the bark transciptomes of Hevea brasiliensis induced with ethephon for 8 h (E8) and 24 h (E24) were performed. 51,965,770, 52,303,714 and 53,177,976 high-quality clean reads from E8, E24 and C (control) samples were assembled into 81,335, 80,048 and 80,800 unigenes respectively, with a total of 84,425 unigenes and an average length of 1,101 bp generated. 10,216 and 9,374 differentially expressed genes (DEGs) in E8 and E24 compared with C were respectively detected. The expression of several enzymes in crucial points of regulation in glycolysis were up-regulated and DEGs were not significantly enriched in isopentenyl diphosphate (IPP) biosynthesis pathway. In addition, up-regulated genes of great regulatory importance in carbon fixation (Calvin cycle) were identified. CONCLUSIONS: The rapid acceleration of glycolytic pathway supplying precursors for the biosynthesis of IPP and natural rubber, instead of rubber biosynthesis per se, may be responsible for ethylene stimulation of latex yield in rubber tree. The elevated rate of flux throughout the Calvin cycle may account for some durability of ethylene-induced stimulation. Our finding lays the foundations for molecular diagnostic and genetic engineering for high-yielding improvement of rubber tree.

Application effects of targeted nursing model in patients undergoing thyroid surgery and its influence on patients' negative emotions.

OBJECTIVE: To explore the effectiveness of a targeted nursing model for patients undergoing thyroid surgery, and to analyse the influence of intervention on the negative emotions of patients. METHODS: Eighty patients who received thyroid surgery in our hospital were enrolled and divided into a study group (n=40, given targeted nursing) and a control group (n=40, given routine surgical nursing) according to the difference of intervention measures. The postoperative bed-leaving time, hospitalization time, medical expenses, drainage tube indwelling time and incidence of postoperative adverse reactions were compared between the two groups. The degree of pain, anxiety and depression was compared between the two groups at 1 d, 3 d, 5 d, and 7 d after surgery. The scales of voice handicap index (VHI-10) and standard swallowing assessment (SSA) were used to evaluate voice quality and swallowing function in the two groups. RESULTS: The postoperative bed-leaving time, hospitalization time, medical expenses, drainage tube indwelling time and incidence of postoperative adverse reactions of patients in the study group were lower than those in the control group (P<0.05). The scores of visual analogue scale (VAS), self-rating anxiety scale (SAS) and self-rating depression scale (SDS) in the study group at 3 d, 5 d and 7 d after surgery were lower than those in the control group (P<0.05). The scores of VHI-10 and SSA in the study group were lower than those in the control group at 7 d and 30 d after surgery (P<0.05). CONCLUSION: Targeted nursing for patients undergoing thyroid surgery can help accelerate the improvement of postoperative clinical symptoms, relieve the unhealthy emotions and pain of patients, and help improve their voice quality and swallowing function, which also has a positive effect on reducing postoperative complications. Therefore, it is worthy of clinical popularization and application.

The effect of online training-based continuous nursing care for rectal cancer-patients undergoing permanent colostomy.

OBJECTIVE: The study explored and analyzed the effects of online training based continuous nursing care on the health-related life quality and self-care ability of rectal cancer patients undergoing permanent colostomy. METHODS: A total of 119 patients who were hospitalized and underwent permanent colostomy due to rectal cancer from January 2018 to December 2019 were collected as research subjects and were divided into the control group (n=57) and the observation group (n=62) based on their admission time. The control group received routine nursing, while the observation group was treated with online training based continuous nursing care in addition to routine nursing. Both groups' self-efficacy, self-care ability, quality of life, psychological status and complications within 6 months after discharge were compared. RESULTS: Both groups had increased scores in self-efficacy, and their dimensional scores and total scores of self-care ability after intervention were higher compared with pre-intervention (P<0.05), and the indexes of the observation group after intervention were significantly higher than that of the control group (P<0.05). The two groups had remarkably increased SF-36 scores of each dimension after intervention compared with pre-intervention (P<0.05), and the observation group had apparently higher SF-36 scores than the control group after intervention (P<0.05). The two groups had increased SAS and SDS grades in post-intervention compared with pre-intervention (P<0.05), and the observation group had notably higher SAS and SDS scores than the control group (P<0.05). The complication rate within 6 months after discharge in the observation group was obviously lower than which in the control group (P<0.05). CONCLUSION: An online training based continuous caring model can effectively improve the self-care ability and self-efficacy of rectal cancer patients with permanent enterostomy, thus promoting better life quality and psychological states, and effectively reducing the incidence of complications after discharge.

The effect of evidence-based nursing program of progressive functional exercise of affected limbs on patients with breast cancer-related lymphoedema.

OBJECTIVE: This study explored and analyzed the effect of evidence-based nursing program of progressive exercise on patients with breast cancer-related lymphoedema. METHODS: 78 breast cancer patients who underwent breast cancer surgery in our hospital from January to December 2018 were chosen as the control group, and 83 patients enrolled from January to December 2019 with the same condition were selected as the observation group. The control group was given routine nursing measures after surgery, while the observation group was given the evidence-based nursing (EBN) program of progressive functional exercise on affected limbs after breast cancer surgery. The postoperative lymphedema, function recovery of upper limb, score of quality life and the satisfaction of patients to nursing were compared between the two groups. RESULTS: The degree of lymphedema in the observation group was significantly lower than that in the control group 4 weeks after surgery (P<0.05). The limb lifting function, abduction function and rotatory function of the observation group were significantly superior to those of the control group (P<0.05). The scores of physiological status, emotional status, functional status and additional concerns in the observation group were significantly higher than those in the control group 4 weeks after operation (25.46±3.97 vs. 16.95±4.17; 24.74±3.11 vs. 17.42±2.86; 25.48±1.69 vs. 25.48±1.69; 24.51±4.12 vs. 18.32±2.56) (P<0.05). There was no significant difference in social/family status scores between the two groups (P>0.05). Additionally, the satisfaction of patients in the observation group to nursing care was also significantly higher than that in control group (P<0.05). CONCLUSION: The evidence-based nursing program of progressive exercise can effectively reduce the lymphedema of patients after breast cancer surgery, improve their postoperative upper limbs function, and effectively promote the quality of life and nursing satisfaction, which is worthy of clinical promotion.

Patellin1 negatively regulates plant salt tolerance by attenuating nitric oxide accumulation in Arabidopsis.

Salt stress adversely affects plant growth and development. Multiple adaptive mechanisms have been used for plant salt tolerance. We previously reported that membrane trafficking-related protein patellin1 (PATL1) negatively regulates plant salt tolerance. Here, we characterized that Arabidopsis PATL1 negatively modulates nitric oxide (NO) accumulation upon salt exposure. Our work revealed a functional link between salt response and NO signaling.