scholarly journals Roles of a Cysteine Desulfhydrase LCD1 in Regulating Leaf Senescence in Tomato

2021 ◽  
Vol 22 (23) ◽  
pp. 13078
Author(s):  
Kangdi Hu ◽  
Xiangjun Peng ◽  
Gaifang Yao ◽  
Zhilin Zhou ◽  
Feng Yang ◽  
...  
Keyword(s):  
Leaf Senescence ◽  
Stress Responses ◽  
Chlorophyll Degradation ◽  
Wild Type ◽  
Tomato Seedlings ◽  
Ros Accumulation ◽  
Physiological Analysis ◽  
Mda Content ◽  
Cysteine Desulfhydrase ◽  
H2s Production

Hydrogen sulfide (H2S), a novel gasotransmitter in both mammals and plants, plays important roles in plant development and stress responses. Leaf senescence represents the final stage of leaf development. The role of H2S-producing enzyme L-cysteine desulfhydrase in regulating tomato leaf senescence is still unknown. In the present study, the effect of an L-cysteine desulfhydrase LCD1 on leaf senescence in tomato was explored by physiological analysis. LCD1 mutation caused earlier leaf senescence, whereas LCD1 overexpression significantly delayed leaf senescence compared with the wild type in 10-week tomato seedlings. Moreover, LCD1 overexpression was found to delay dark-induced senescence in detached tomato leaves, and the lcd1 mutant showed accelerated senescence. An increasing trend of H2S production was observed in leaves during storage in darkness, while LCD1 deletion reduced H2S production and LCD1 overexpression produced more H2S compared with the wild-type control. Further investigations showed that LCD1 overexpression delayed dark-triggered chlorophyll degradation and reactive oxygen species (ROS) accumulation in detached tomato leaves, and the increase in the expression of chlorophyll degradation genes NYC1, PAO, PPH, SGR1, and senescence-associated genes (SAGs) during senescence was attenuated by LCD1 overexpression, whereas lcd1 mutants showed enhanced senescence-related parameters. Moreover, a correlation analysis indicated that chlorophyll content was negatively correlated with H2O2 and malondialdehyde (MDA) content, and also negatively correlated with the expression of chlorophyll degradation-related genes and SAGs. Therefore, these findings increase our understanding of the physiological functions of the H2S-generating enzyme LCD1 in regulating leaf senescence in tomato.

scholarly journals Triticum Aestivum L. cv. Guizi 1 ANS-6D Positively Regulates Leaf Senescence Through the Abscisic Acid Mediated Chlorophyll Degradation in Tobacco

2021 ◽  
Author(s):  
Luhua Li ◽  
Chang An ◽  
Zhongni Wang ◽  
Fumin Xiong ◽  
Yingxi Wang ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Abscisic Acid ◽  
Leaf Senescence ◽  
Triticum Aestivum L ◽  
Degradation Pathway ◽  
Chlorophyll Degradation ◽  
Anthocyanin Synthesis ◽  
Marker Genes ◽  
Wild Type ◽  
Transgenic Lines

Abstract Anthocyanidin synthase (ANS) is involved in the synthesis of anthocyanins, which are important phytonutrients because of their beneficial effects on human health. Here, we identified ANS-6D of purple-colored Triticum aestivum L. cv. Guizi 1 (Gz) that is involved in leaf senescence through the abscisic acid (ABA) mediated chlorophyll degradation pathway in tobacco. After characterizing the leaf-senescence phenotype in GzANS-6D overexpression (OxGzANS-6D) lines, we found that the increased anthocyanin accumulation and decreased chlorophyll content in OxGzANS-6D lines were closely correlated with the expression levels of anthocyanin synthesis-related structural genes and senescence marker genes, as well as the accumulation of reactive oxygen species. The endogenous ABA content increased and ethylene content decreased in OxGzANS-6D transgenic lines compared with wild type. Additionally, the levels of the abscisic acid-responsive transcription factors ABF1 and ABF2, as well as those of chlorophyll degradation-related genes (PAO, NYC, SGR and CHL), were significantly higher in OxGzANS-6D transgenic lines than in wild type. Furthermore, we found that GzABF1 and NtABF1 binds to the promoter of GzANS-6D, and NtABF2 binds to the promoter of NtSGR. Thus, GzANS-6D participated in leaf senescence through ABA-mediated chlorophyll degradation, and ABF1/2 play important role in GzANS-6D functions.

scholarly journals Overexpression of a Malus baccata NAC Transcription Factor Gene MbNAC25 Increases Cold and Salinity Tolerance in Arabidopsis

2020 ◽  
Vol 21 (4) ◽  
pp. 1198 ◽  
Author(s):  
Deguo Han ◽  
Man Du ◽  
Zhengyi Zhou ◽  
Shuang Wang ◽  
Tiemei Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Stress Responses ◽  
Apical Meristem ◽  
High Salinity ◽  
Transgenic Arabidopsis ◽  
Wild Type ◽  
Mda Content ◽  
High Salt Stress ◽  
Malus Baccata ◽  
Nac Family

NAC (no apical meristem (NAM), Arabidopsis thaliana transcription activation factor (ATAF1/2) and cup shaped cotyledon (CUC2)) transcription factors play crucial roles in plant development and stress responses. Nevertheless, to date, only a few reports regarding stress-related NAC genes are available in Malus baccata (L.) Borkh. In this study, the transcription factor MbNAC25 in M. baccata was isolated as a member of the plant-specific NAC family that regulates stress responses. Expression of MbNAC25 was induced by abiotic stresses such as drought, cold, high salinity and heat. The ORF of MbNAC25 is 1122 bp, encodes 373 amino acids and subcellular localization showed that MbNAC25 protein was localized in the nucleus. In addition, MbNAC25 was highly expressed in new leaves and stems using real-time PCR. To analyze the function of MbNAC25 in plants, we generated transgenic Arabidopsis plants that overexpressed MbNAC25. Under low-temperature stress (4 °C) and high-salt stress (200 mM NaCl), plants overexpressing MbNAC25 enhanced tolerance against cold and drought salinity conferring a higher survival rate than that of wild-type (WT). Correspondingly, the chlorophyll content, proline content, the activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were significantly increased, while malondialdehyde (MDA) content was lower. These results indicated that the overexpression of MbNAC25 in Arabidopsis plants improved the tolerance to cold and salinity stress via enhanced scavenging capability of reactive oxygen species (ROS).

scholarly journals Characterization of the Function of Two S1Fa-Like Family Genes From Populus trichocarpa

2021 ◽  
Vol 12 ◽  
Author(s):  
Huimin Zhao ◽  
Yani Niu ◽  
Hao Dong ◽  
Yaqi Jia ◽  
Yucheng Wang
Keyword(s):  
Drought Tolerance ◽  
Populus Trichocarpa ◽  
Wild Type ◽  
Small Molecular Weight ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Ros Accumulation ◽  
Drought And Salt Stress ◽  
Mda Content

S1Fa-like transcription factors (TFs) are small molecular weight proteins that contain both nuclear localization and DNA binding domains. However, the functions of S1Fa-like TFs are poorly understood. In the present study, we identified the S1Fa-like TFs from the Populus trichocarpa genome, which revealed two S1Fa-like TF genes, PtS1Fa1 and PtS1Fa2. PtS1Fa1 and PtS1Fa2 expression was suppressed by drought and salt stress, and was also significantly altered by ABA, MeJA, or SA treatment. Both PtS1Fa1 and PtS1Fa2 are nuclear proteins. Transgenic P. trichocarpa plants overexpressing PtS1Fa1 and PtS1Fa2, respectively, were generated. The plants overexpressing PtS1Fa2 showed increased fresh weight, chlorophyll content, and root length and weight compared with those in wild-type (WT) P. trichocarpa under drought conditions. Meanwhile, these phenotype traits of plants overexpressing PtS1Fa1 were similar to those of WT plants. Furthermore, overexpression of PtS1Fa2 reduced the malondialdehyde (MDA) content, electrolyte leakage, H2O2 and O2- contents, and increased superoxide dismutase (SOD) and peroxidase (POD) activities. The expression of SOD and POD was also induced by PtS1Fa2. However, overexpression of PtS1Fa1 failed to affect any of these physiological parameters or SOD and POD gene expression. These results suggested that PtS1Fa2 plays a role in drought tolerance, and confers drought tolerance by increase antioxidant activity to reduce reactive oxygen species (ROS) accumulation.

scholarly journals InsP7is a small-molecule regulator of NUDT3-mediated mRNA decapping and processing-body dynamics

2020 ◽  
Vol 117 (32) ◽  
pp. 19245-19253 ◽  
Author(s):  
Soumyadip Sahu ◽  
Zhenzhen Wang ◽  
Xinfu Jiao ◽  
Chunfang Gu ◽  
Nikolaus Jork ◽  
...  
Keyword(s):  
Stress Responses ◽  
Messenger Rna ◽  
Control Process ◽  
Stem Cell Differentiation ◽  
Wild Type ◽  
Inositol Pyrophosphate ◽  
Body Dynamics ◽  
Processing Body ◽  
The Stability

Regulation of enzymatic 5′ decapping of messenger RNA (mRNA), which normally commits transcripts to their destruction, has the capacity to dynamically reshape the transcriptome. For example, protection from 5′ decapping promotes accumulation of mRNAs into processing (P) bodies—membraneless, biomolecular condensates. Such compartmentalization of mRNAs temporarily removes them from the translatable pool; these repressed transcripts are stabilized and stored until P-body dissolution permits transcript reentry into the cytosol. Here, we describe regulation of mRNA stability and P-body dynamics by the inositol pyrophosphate signaling molecule 5-InsP7(5-diphosphoinositol pentakisphosphate). First, we demonstrate 5-InsP7inhibits decapping by recombinant NUDT3 (Nudix [nucleoside diphosphate linked moiety X]-type hydrolase 3) in vitro. Next, in intact HEK293 and HCT116 cells, we monitored the stability of a cadre of NUDT3 mRNA substrates following CRISPR-Cas9 knockout ofPPIP5Ks(diphosphoinositol pentakisphosphate 5-kinases type 1 and 2, i.e.,PPIP5KKO), which elevates cellular 5-InsP7levels by two- to threefold (i.e., within the physiological rheostatic range). ThePPIP5KKO cells exhibited elevated levels of NUDT3 mRNA substrates and increased P-body abundance. Pharmacological and genetic attenuation of 5-InsP7synthesis in the KO background reverted both NUDT3 mRNA substrate levels and P-body counts to those of wild-type cells. Furthermore, liposomal delivery of a metabolically resistant 5-InsP7analog into wild-type cells elevated levels of NUDT3 mRNA substrates and raised P-body abundance. In the context that cellular 5-InsP7levels normally fluctuate in response to changes in the bioenergetic environment, regulation of mRNA structure by this inositol pyrophosphate represents an epitranscriptomic control process. The associated impact on P-body dynamics has relevance to regulation of stem cell differentiation, stress responses, and, potentially, amelioration of neurodegenerative diseases and aging.

scholarly journals Nicotinamide Supplementation Improves Oocyte Quality and Offspring Development by Modulating Mitochondrial Function in an Aged Caenorhabditis elegans Model

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 519
Author(s):  
Hyemin Min ◽  
Mijin Lee ◽  
Kyoung Sang Cho ◽  
Hyunjung Jade Lim ◽  
Yhong-Hee Shim
Keyword(s):  
Caenorhabditis Elegans ◽  
Mitochondrial Function ◽  
Stress Responses ◽  
Oocyte Quality ◽  
Embryonic Lethality ◽  
Reproductive Aging ◽  
Control Female ◽  
Offspring Development ◽  
Developmental Growth ◽  
Ros Accumulation

Aging is associated with a decline in the quality of biological functions. Among the aging processes, reproductive aging is a critical process because of its intergenerational effects. However, the mechanisms underlying reproductive aging remain largely unknown. Female reproductive aging is the primary reason for limited fertility in mammals. Therefore, we attempted to investigate a modulator that can control female reproductive aging using a Caenorhabditis elegans model. In the present study, we examined the role of nicotinamide (NAM) in oocyte quality and offspring development. The levels of reactive oxygen species (ROS) and oxidative stress responses in aged oocytes, embryonic lethality, and developmental growth of the offspring were examined with maternal NAM supplementation. Supplementation with NAM improved oocyte quality, decreased embryonic lethality, and promoted germ cell apoptosis. Furthermore, NAM supplementation in aged mothers reduced ROS accumulation and improved mitochondrial function in oocytes. Consequently, the developmental growth and motility of offspring were improved. These findings suggest that NAM supplementation improves the health of the offspring produced by aged mothers through improved mitochondrial function. Taken together, our results imply that NAM supplementation in the aged mother improves oocyte quality and protects offspring by modulating mitochondrial function.

scholarly journals Contrasting roles of GmNAC065 and GmNAC085 in natural senescence, plant development, multiple stresses and cell death responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno Paes Melo ◽  
Isabela Tristan Lourenço-Tessutti ◽  
Otto Teixeira Fraga ◽  
Luanna Bezerra Pinheiro ◽  
Camila Barrozo de Jesus Lins ◽  
...  
Keyword(s):  
Cell Death ◽  
Plant Development ◽  
Stress Responses ◽  
Regulatory Networks ◽  
Lower Stress ◽  
Multiple Stresses ◽  
Gene Sets ◽  
Ros Accumulation ◽  
Stress Dependent ◽  
Senescence Associated Genes

AbstractNACs are plant-specific transcription factors involved in controlling plant development, stress responses, and senescence. As senescence-associated genes (SAGs), NACs integrate age- and stress-dependent pathways that converge to programmed cell death (PCD). In Arabidopsis, NAC-SAGs belong to well-characterized regulatory networks, poorly understood in soybean. Here, we interrogated the soybean genome and provided a comprehensive analysis of senescence-associated Glycine max (Gm) NACs. To functionally examine GmNAC-SAGs, we selected GmNAC065, a putative ortholog of Arabidopsis ANAC083/VNI2 SAG, and the cell death-promoting GmNAC085, an ANAC072 SAG putative ortholog, for analyses. Expression analysis of GmNAC065 and GmNAC085 in soybean demonstrated (i) these cell death-promoting GmNACs display contrasting expression changes during age- and stress-induced senescence; (ii) they are co-expressed with functionally different gene sets involved in stress and PCD, and (iii) are differentially induced by PCD inducers. Furthermore, we demonstrated GmNAC065 expression delays senescence in Arabidopsis, a phenotype associated with enhanced oxidative performance under multiple stresses, higher chlorophyll, carotenoid and sugar contents, and lower stress-induced PCD compared to wild-type. In contrast, GmNAC085 accelerated stress-induced senescence, causing enhanced chlorophyll loss, ROS accumulation and cell death, decreased antioxidative system expression and activity. Accordingly, GmNAC065 and GmNAC085 targeted functionally contrasting sets of downstream AtSAGs, further indicating that GmNAC85 and GmNAC065 regulators function inversely in developmental and environmental PCD.

Identification of Arabidopsis stay-green mutants with a functional ethylene-response pathway

2010 ◽  
Vol 14 ◽  
pp. 119-129
Author(s):  
R. Shirzadian-Khorramabad ◽  
H.C. Jing ◽  
J. Hille ◽  
P.P. Dijkwel
Keyword(s):  
Shelf Life ◽  
Leaf Senescence ◽  
Plant Hormone ◽  
Floral Induction ◽  
Growth Conditions ◽  
Pleiotropic Effects ◽  
Wild Type ◽  
Stay Green ◽  
Ethylene Response ◽  
Determinant Factor

Natural or harvest-induced senescence is a major determinant factor causing crop losses. The plant hormone ethylene is a strong inducer of senescence and decreasing the ethylene response can reduce senescence, albeit often with undesirable pleiotropic effects. We took advantage of ethylene-induced leaf senescence as a tool to screen for late senescence Arabidopsis mutants that still have a functional ethylenesignalling pathway. Sixteen Arabidopsis onset of leaf death (old) mutants were selected that stayed green after treatment with ethylene. While all the mutants responded to ethylene in a triple response assay, ten mutants responded to the treatment in the same way as the wild type. These ten mutants showed limited pleiotropic effects when grown under standard growth conditions but nine mutants flowered slightly later than the wild type. Genetic characterisation of a subset of the mutants identified several independent loci controlling the leaf senescence process. The approach resulted in the isolation of several stay-green mutants with a functional ethylene response pathway. The late senescence mutants show extended leaf longevity and further research may advance the field of pre- or post-harvest senescence technology. The results, moreover, suggest that there is a correlation between senescence and floral induction. Keywords: Senescence, Arabidopsis, ethylene, mutant, shelf life

scholarly journals Alternative Pathway is Involved in Nitric Oxide-Enhanced Tolerance to Cadmium Stress in Barley Roots

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 557 ◽  
Author(s):  
Li He ◽  
Xiaomin Wang ◽  
Ruijun Feng ◽  
Qiang He ◽  
Shengwang Wang ◽  
...  
Keyword(s):  
Stress Tolerance ◽  
Alternative Pathway ◽  
Cadmium Stress ◽  
Cd Stress ◽  
No Donor ◽  
Ros Accumulation ◽  
Mda Content ◽  
Scavenging Enzymes ◽  
Tolerance To Cadmium

Alternative pathway (AP) has been widely accepted to be involved in enhancing tolerance to various environmental stresses. In this study, the role of AP in response to cadmium (Cd) stress in two barley varieties, highland barley (Kunlun14) and barley (Ganpi6), was investigated. Results showed that the malondialdehyde (MDA) content and electrolyte leakage (EL) level under Cd stress increased in two barley varieties. The expressions of alternative oxidase (AOX) genes (mainly AOX1a), AP capacity (Valt), and AOX protein amount were clearly induced more in Kunlun14 under Cd stress, and these parameters were further enhanced by applying sodium nitroprussid (SNP, a NO donor). Moreover, H2O2 and O2− contents were raised in the Cd-treated roots of two barley varieties, but they were markedly relieved by exogenous SNP. However, this mitigating effect was aggravated by salicylhydroxamic acid (SHAM, an AOX inhibitor), suggesting that AP contributes to NO-enhanced Cd stress tolerance. Further study demonstrated that the effect of SHAM application on reactive oxygen species (ROS)-related scavenging enzymes and antioxidants was minimal. These observations showed that AP exerts an indispensable function in NO-enhanced Cd stress tolerance in two barley varieties. AP was mainly responsible for regulating the ROS accumulation to maintain the homeostasis of redox state.

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