| 1. |
- Ali, Muhammad Amjad, et al.
(författare)
-
Transcription factors WRKY11 and WRKY17 are involved in abiotic stress responses in Arabidopsis
- 2018
-
Ingår i: Journal of plant physiology (Print). - : Elsevier. - 0176-1617 .- 1618-1328. ; 226, s. 12-21
-
Tidskriftsartikel (refereegranskat)abstract
- Plant WRKY transcription factors play a vital role in abiotic stress tolerance and regulation of plant defense responses. This study examined AtWRKY11 and AtWRKY17 expression under ABA, salt, and osmotic stress at different developmental stages in Arabidopsis. We used reverse transcriptase PCR, quantitative real-time PCR, and promoter:GUS lines to analyze expression. Both genes were upregulated in response to abiotic stress. Next, we applied the same stressors to seedlings of T-DNA insertion wrky11 and 17 knock-out mutants (single and double). Under stress, the mutants exhibited slower germination and compromised root growth compared with the wild type. In most cases, double-mutant seedlings were more affected than single mutants. These results suggest that wrky11 and wrky17 are not strictly limited to plant defense responses but are also involved in conferring stress tolerance.
|
|
| 2. |
- Asaf, Sajjad, et al.
(författare)
-
The complete chloroplast genome of wild rice (Oryza minuta) and its comparison to related species
- 2017
-
Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Oryza minuta, a tetraploid wild relative of cultivated rice (family Poaceae), possesses a BBCC genome and contains genes that confer resistance to bacterial blight (BB) and white-backed (WBPH) and brown (BPH) plant hoppers. Based on the importance of this wild species, this study aimed to understand the phylogenetic relationships of O. minuta with other Oryza species through an in-depth analysis of the composition and diversity of the chloroplast (cp) genome. The analysis revealed a cp genome size of 135,094 bp with a typical quadripartite structure and consisting of a pair of inverted repeats separated by small and large single copies, 139 representative genes, and 419 randomly distributed microsatellites. The genomic organization, gene order, GC content and codon usage are similar to those of typical angiosperm cp genomes. Approximately 30 forward, 28 tandem and 20 palindromic repeats were detected in the O. minuta cp genome. Comparison of the complete O. minuta cp genome with another eleven Oryza species showed a high degree of sequence similarity and relatively high divergence of intergenic spacers. Phylogenetic analyses were conducted based on the complete genome sequence, 65 shared genes and matK gene showed same topologies and O. minuta forms a single clade with parental O. punctata. Thus, the complete O. minuta cp genome provides interesting insights and valuable information that can be used to identify related species and reconstruct its phylogeny.
|
|
| 3. |
- Imran, Muhammad, et al.
(författare)
-
Exogenous Melatonin mediates the regulation of endogenous nitric oxide in Glycine max L. to reduce effects of drought stress
- 2021
-
Ingår i: Environmental and Experimental Botany. - : Elsevier. - 0098-8472 .- 1873-7307. ; 188
-
Tidskriftsartikel (refereegranskat)abstract
- Drought stress retards plant growth and yield. Melatonin and nitric oxide (NO) have demonstrated their potential role against abiotic stresses; however, the underlying molecular mechanism by which they interact and extend drought stress tolerance has not been fully elucidated. Herein, the current study was performed to establish the optimum beneficial concentration of MT and NO in combating drought stress and later understand its responses at biochemical, and molecular levels. Results showed exogenous MT, and sodium nitroprusside (SNP as NO donor) have counteracted drought-induced growth inhibition of soybean (Glycine max L.) by increasing plant biomass, photosynthesis efficiency and water content and reducing reactive oxygen species accumulation. MT and NO treatments showed reduced lipid peroxidation and improved defense responses via significantly higher antioxidant enzyme activities than control during drought. Surprisingly, endogenous abscisic acid (ABA) contents and gene expression of its synthesis and ABA-responsive proteins and their promoters were significantly decreased in drought by MT + NO. This was coupled with an increase in endogenous MT levels. In endo-NO regulations, S-nitrosoglutathione was increased, but L-NAME (NO inhibitor) and cPTIO (NO scavenger) decreased the S-nitrosothiol (SNO) contents, which was followed by the increased expression of NO-synthesis-related-genes by MT + NO. Interestingly, MT + NO-induced drought stress tolerance was coupled with increased expression of transcription factors such as GmWRKY27 and GmMYB174. Conclusively, the physiological, antioxidant, and molecular analysis showed that MT triggers downregulated NO accumulation, promoting tolerance against drought stress.
|
|
| 4. |
- Kamran, Muhammad, et al.
(författare)
-
Endophyte-mediated stress tolerance in plants : a sustainable strategy to enhance resilience and assist crop improvement
- 2022
-
Ingår i: Cells. - : MDPI. - 2073-4409. ; 11:20
-
Forskningsöversikt (refereegranskat)abstract
- Biotic and abiotic stresses severely affect agriculture by affecting crop productivity, soil fertility, and health. These stresses may have significant financial repercussions, necessitating a practical, cost-effective, and ecologically friendly approach to lessen their negative impacts on plants. Several agrochemicals, such as fertilizers, pesticides, and insecticides, are used to improve plant health and protection; however, these chemical supplements have serious implications for human health. Plants being sessile cannot move or escape to avoid stress. Therefore, they have evolved to develop highly beneficial interactions with endophytes. The targeted use of beneficial plant endophytes and their role in combating biotic and abiotic stresses are gaining attention. Therefore, it is important to experimentally validate these interactions and determine how they affect plant fitness. This review highlights research that sheds light on how endophytes help plants tolerate biotic and abiotic stresses through plant–symbiont and plant–microbiota interactions. There is a great need to focus research efforts on this vital area to achieve a system-level understanding of plant–microbe interactions that occur naturally.
|
|
| 5. |
- Kamran, Muhammad, et al.
(författare)
-
Hydroquinone; a novel bioactive compound from plant-derived smoke can cue seed germination of lettuce
- 2017
-
Ingår i: Frontiers in Chemistry. - : Frontiers Media S.A.. - 2296-2646. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- Plant-derived smoke has been known to play an important role in distribution and growth of vegetation. Using a proficiently designed furnace, we extracted smoke from the leaves of four plant viz. Helianthus annuus,Aloe vera,Ginkgo biloba, and Cymbopogon jwarancusa. Smoke dilutions obtained from these plants were obtained in different concentrations to identify potential lettuce growth promoting smoke solution. Results revealed that smoke obtained from G. biloba significantly enhanced the lettuce seed germination. This solution was then partitioned into ethyl acetate, dichloromethane, n-hexane, chloroform and ether fractions. Ethyl acetate fraction was found to be potent to enhance seed germination. This fraction was subjected to column chromatography and spectroscopic techniques to obtain compound 1. This compound was identified as hydroquinone using 1D and 2D NMR techniques. At low concentrations (5, 10, and 20 ppm), compound 1 enhanced the lettuce seed germination; however, higher concentrations inhibited its growth as compared to control.
|
|
| 6. |
- Al Azzawi, Tiba Nazar Ibrahim, et al.
(författare)
-
Evaluation of Iraqi Rice Cultivars for Their Tolerance to Drought Stress
- 2020
-
Ingår i: Agronomy. - : MDPI. - 2073-4395. ; 10:11
-
Tidskriftsartikel (refereegranskat)abstract
- Drought stress is a serious problem around the globe and particularly in the Republic of Iraq. Rice is the third most consumed crop for the Iraqi people; however, its cultivation and production is very low due to several challenges including drought. The current study was performed to evaluate five Iraqi rice cultivars along with relevant (drought-tolerant and drought-susceptible) controls under drought stress, either by treatment with 10% PEG (polyethylene glycol) or through water withholding to induce natural drought stress. The phenotypes of all the cultivars were evaluated and the transcriptional responses of key drought-responsive candidate genes, identified through the EST-SSR marker-based approach, were studied. We also studied transcript accumulation of drought-related transcriptional factors, such as OsGRASS23, OsbZIP12, and OsDREB2A. Moreover, the reference cultivars also included a drought-tolerant inter-specific cultivar Nerica 7 (a cross between Oryza sativa ssp. indica X O. glaberrima). Among the cultivars, the more drought-tolerant phenotypic characteristics and higher transcript accumulation of drought-related marker genes OsE647 and OsE1899 and transcriptional factors OsGRASS23, OsbZIP12, and OsDREB2A were observed in four (out of five) significantly drought-tolerant Iraqi cultivars; Mashkab, followed by Furat, Yasmen, and Amber 33. On another note, Amber Barka was found to be significantly drought susceptible. Mashkab and Amber Barka were found to be the most drought-tolerant and-susceptible cultivars, respectively. The identified tolerant cultivars may potentially serve as a genetic source for the incorporation of drought-tolerant phenotypes in rice.
|
|
| 7. |
- Asaf, Sajjad, et al.
(författare)
-
Comparative analysis of complete plastid genomes from wild soybean (Glycine soja) and nine other Glycine species
- 2017
-
Ingår i: PLOS ONE. - : Public Library Science (PLOS). - 1932-6203. ; 12:8
-
Tidskriftsartikel (refereegranskat)abstract
- The plastid genomes of different plant species exhibit significant variation, thereby providing valuable markers for exploring evolutionary relationships and population genetics. Glycine soja (wild soybean) is recognized as the wild ancestor of cultivated soybean (G. max), representing a valuable genetic resource for soybean breeding programmes. In the present study, the complete plastid genome of G. soja was sequenced using Illumina paired-end sequencing and then compared it for the first time with previously reported plastid genome sequences from nine other Glycine species. The G. soja plastid genome was 152,224 bp in length and possessed a typical quadripartite structure, consisting of a pair of inverted repeats (IRa/IRb; 25,574 bp) separated by small (178,963 bp) and large (83,181 bp) single-copy regions, with a 51-kb inversion in the large single-copy region. The genome encoded 134 genes, including 87 protein-coding genes, eight ribosomal RNA genes, and 39 transfer RNA genes, and possessed 204 randomly distributed microsatellites, including 15 forward, 25 tandem, and 34 palindromic repeats. Whole-plastid genome comparisons revealed an overall high degree of sequence similarity between G. max and G. gracilis and some divergence in the intergenic spacers of other species. Greater numbers of indels and SNP substitutions were observed compared with G. cyrtoloba. The sequence of the accD gene from G. soja was highly divergent from those of the other species except for G. max and G. gracilis. Phylogenomic analyses of the complete plastid genomes and 76 shared genes yielded an identical topology and indicated that G. soja is closely related to G. max and G. gracilis. The complete G. soja genome sequenced in the present study is a valuable resource for investigating the population and evolutionary genetics of Glycine species and can be used to identify related species.
|
|
| 8. |
- Asaf, Sajjad, et al.
(författare)
-
Osmoprotective functions conferred to soybean plants via inoculation with Sphingomonas sp. LK11 and exogenous trehalose
- 2017
-
Ingår i: Microbiology Research. - : Elsevier. - 0944-5013 .- 1618-0623. ; 205, s. 135-145
-
Tidskriftsartikel (refereegranskat)abstract
- Osmotic stress induced by drought can hinder the growth and yield of crop plants. To understand the eco-physiological role of osmoprotectants, the combined utilization of endophytes and osmolytes (trehalose) can be an ideal strategy used to overcome the adverse effects of drought. Hence, in the present study, we aimed to investigate the role of Sphingomonas sp. LK11, which produces phytohormones and synthesizes trehalose, in improving soybean plant growth under drought-induced osmotic stress (−0.4, −0.9, and −1.2 MPa). The results showed that the inoculation of soybean plants with Sphingomonas sp. LK11 significantly increased plant length, dry biomass, photosynthetic pigments, glutathione, amino acids (proline, glycine, and glutamate), and primary sugars as compared to control plants under varying drought stresses. Trehalose applied to the plant with or without endophyte-inoculation also showed similar plant growth-promoting attributes under stress. Stress exposure significantly enhanced endogenous jasmonic (JA) and abscisic (ABA) acid contents in control plants. In contrast, Sphingomonas sp. LK11-inoculation significantly lowered ABA and JA levels in soybean plants, but these phytohormones increased in response to combined treatments during stress. The drought-induced osmotic stress resistance associated with Sphingomonas sp. LK11 and trehalose was also evidenced by increased mRNA gene expression of soybean dehydration responsive element binding protein (DREB)-type transcription factors (GmDREBa and GmDREB2) and the MYB (myeloblastosis) transcription factor (GmMYBJ1) as compared to the control. In conclusion, our findings demonstrated that inoculation with this endophyte and trehalose improved the negative effects of drought-induced osmotic stress, and it enhanced soybean plant growth and tolerance.
|
|
| 9. |
- Hussain, Adil, et al.
(författare)
-
Nitric oxide mediated transcriptome profiling reveals activation of multiple regulatory pathways in Arabidopsis thaliana
- 2016
-
Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Imbalance between the accumulation and removal of nitric oxide and its derivatives is a challenge faced by all plants at the cellular level, and is especially important under stress conditions. Exposure of plants to various biotic and abiotic stresses causes rapid changes in cellular redox tone potentiated by the rise in reactive nitrogen species that serve as signaling molecules in mediating defensive responses. To understand mechanisms mediated by these signaling molecules, we performed a large-scale analysis of the Arabidopsis transcriptome induced by nitrosative stress. We generated an average of 84 and 91 million reads from three replicates each of control and 1 mM S-nitrosocysteine (CysNO)-infiltrated Arabidopsis leaf samples, respectively. After alignment, more than 95% of all reads successfully mapped to the reference and 32,535 genes and 55,682 transcripts were obtained. CysNO infiltration caused differential expression of 6436 genes (3448 up-regulated and 2988 down-regulated) and 6214 transcripts (3335 up-regulated and 2879 down-regulated) 6 h post-infiltration. These differentially expressed genes were found to be involved in key physiological processes, including plant defense against various biotic and abiotic stresses, hormone signaling, and other developmental processes. After quantile normalization of the FPKM values followed by student's T-test (P < 0.05) we identified 1165 DEGs (463 up-regulated and 702 down-regulated) with at least 2-folds change in expression after CysNO treatment. Expression patterns of selected genes involved in various biological pathways were verified using quantitative real-time PCR. This study provides comprehensive information about plant responses to nitrosative stress at transcript level and would prove helpful in understanding and incorporating mechanisms associated with nitrosative stress responses in plants.
|
|
| 10. |
- Hussain, Adil, et al.
(författare)
-
Nitric oxide synthase in the plant kingdom
- 2021
-
Ingår i: Nitric oxide in plant biology. - : Elsevier. - 9780128187975 ; , s. 43-52
-
Bokkapitel (refereegranskat)abstract
- After the discovery of nitric oxide (NO) as an important signaling molecule in plants, its involvement has been reported in several key physiological processes. At the cellular level, slight alterations in the quantity of NO or its various adducts, also known as reactive nitrogen intermediates (RNIs), have phenomenal implications. In plants this highly reactive, diatomic gaseous molecule regulates a plethora of physiological processes ranging from development, to reproduction, and defense against biotic and abiotic stresses. In animals, NO is produced enzymatically via the nitric oxide synthase (NOS) enzyme. However, after decades of research, it is now clear that in plants there is not one but several routes for NO production. Interestingly the discovery of a NOS enzyme in plants has remained an attractive topic of research for plant scientists over the years; the enzyme still remains elusive. In this chapter we briefly discuss the different pathways responsible for NO production in plants with special emphasis on the enzymatic production. We also discuss the NOS enzyme and its presence in lower and higher plants.
|
|
