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Author(s):  
Laura Laschke ◽  
Vadim Schütz ◽  
Oliver Schackow ◽  
Dieter Sicker ◽  
Lothar Hennig ◽  
...  

AbstractFor the characterization of BOA-OH insensitive plants, we studied the time-dependent effects of the benzoxazolinone-4/5/6/7-OH isomers on maize roots. Exposure of Zea mays seedlings to 0.5 mM BOA-OH elicits root zone-specific reactions by the formation of dark rings and spots in the zone of lateral roots, high catalase activity on root hairs, and no visible defense reaction at the root tip. We studied BOA-6-OH- short-term effects on membrane lipids and fatty acids in maize root tips in comparison to the benzoxazinone-free species Abutilon theophrasti Medik. Decreased contents of phosphatidylinositol in A. theophrasti and phosphatidylcholine in maize were found after 10–30 min. In the youngest tissue, α-linoleic acid (18:2), decreased considerably in both species and recovered within one hr. Disturbances in membrane phospholipid contents were balanced in both species within 30–60 min. Triacylglycerols (TAGs) were also affected, but levels of maize diacylglycerols (DAGs) were almost unchanged, suggesting a release of fatty acids for membrane lipid regeneration from TAGs while resulting DAGs are buildings blocks for phospholipid reconstitution, concomitant with BOA-6-OH glucosylation. Expression of superoxide dismutase (SOD2) and of ER-bound oleoyl desaturase (FAD2-2) genes were contemporaneously up regulated in contrast to the catalase CAT1, while CAT3 was arguably involved at a later stage of the detoxification process. Immuno-responses were not elicited in short-terms, since the expression of NPR1, POX12 were barely affected, PR4 after 6 h with BOA-4/7-OH and PR1 after 24 h with BOA-5/6-OH. The rapid membrane recovery, reactive oxygen species, and allelochemical detoxification may be characteristic for BOA-OH insensitive plants.


2022 ◽  
Vol 119 (1) ◽  
pp. e2101846119
Author(s):  
Tsubasa Kawai ◽  
Kyosuke Shibata ◽  
Ryosuke Akahoshi ◽  
Shunsaku Nishiuchi ◽  
Hirokazu Takahashi ◽  
...  

The development of a plastic root system is essential for stable crop production under variable environments. Rice plants have two types of lateral roots (LRs): S-type (short and thin) and L-type (long, thick, and capable of further branching). LR types are determined at the primordium stage, with a larger primordium size in L-types than S-types. Despite the importance of LR types for rice adaptability to variable water conditions, molecular mechanisms underlying the primordium size control of LRs are unknown. Here, we show that two WUSCHEL-related homeobox (WOX) genes have opposing roles in controlling LR primordium (LRP) size in rice. Root tip excision on seminal roots induced L-type LR formation with wider primordia formed from an early developmental stage. QHB/OsWOX5 was isolated as a causative gene of a mutant that is defective in S-type LR formation but produces more L-type LRs than wild-type (WT) plants following root tip excision. A transcriptome analysis revealed that OsWOX10 is highly up-regulated in L-type LRPs. OsWOX10 overexpression in LRPs increased the LR diameter in an expression-dependent manner. Conversely, the mutation in OsWOX10 decreased the L-type LR diameter under mild drought conditions. The qhb mutants had higher OsWOX10 expression than WT after root tip excision. A yeast one-hybrid assay revealed that the transcriptional repressive activity of QHB was lost in qhb mutants. An electrophoresis mobility shift assay revealed that OsWOX10 is a potential target of QHB. These data suggest that QHB represses LR diameter increase, repressing OsWOX10. Our findings could help improve root system plasticity under variable environments.


2022 ◽  
Author(s):  
Yuebin Xie ◽  
Muhammad Umar Khan ◽  
Chaojie Lan ◽  
Peiying Weng ◽  
Jingnan Zou ◽  
...  

Abstract Chilling is an environmental phenomenon that hampers the plant growth. Related studies are mainly on based on the aerial plant parts. While, below ground to rhizosphere microbiome have been neglected under low temperature stress. The overexpression of Lsi1 in Dular significantly enhances its proline concentration compared with wild type Dular. This overexpression phenomenon maintains the osmotic balance of cells through influx of Ca2+, K+, H+ and efflux of Na+. The calcium deposition and the activity of plasma membrane H+-ATPase determined in root tip was consistent with the obtained ion flux results. In addition, the high-throughput sequencing results showed significant variation among identified 84 genera in different rhizocompartments (rhizosphere, rhizoplane and endosphere). The identified bacteria were associated with photosynthesis, energy metabolism, nitrogen fixation and defense, which were significantly increased in overexpressed plant. While, the number of pathogenic microorganisms associating were significantly reduced. Our findings suggests that the stability of ion balance in overexpressed plant roots affects the structure of microbial community in soil. To conclude, the over expression of Lsi1 gene enhanced cold tolerance of rice and its underlying mechanisms were comprehensively analyzed which can further impart its role in the stress tolerant rice plants.


PROTOPLASMA ◽  
2022 ◽  
Author(s):  
Javier Raya-González ◽  
Adrián Ávalos-Rangel ◽  
León Francisco Ruiz-Herrera ◽  
Juan José Valdez-Alarcón ◽  
José López-Bucio

Author(s):  
Gopikrishnan Venugopal ◽  
Radhakrishnan Manikkam ◽  
Manigundan Kaari ◽  
Shanmugasundaram Thangavel ◽  
Jerrine Joseph

Author(s):  
Himshikha Yadav ◽  
Sushil Kumar

The leaves of Aloe barbadensis are used in traditional and modern systems of medicine. The aim of this study was to evaluate the cytotoxic potentialities of aqueous solution of Aloe barbadensis leaves on Trigonella foenum-graecum root tip meristem cells using a cytogenetic approach. Treatments with various concentrations of Aloe barbadensis leaf extract to Trigonella foenum-graecum root meristem cells showed mito-inhibition and induced several chromosomal aberrations as chromsomal breakage, fragmentation, scattering, stickiness etc.


2021 ◽  
pp. 30-37
Author(s):  
Christa M. Hoffmann ◽  
Gunnar Kleuker ◽  
André Wauters ◽  
William English ◽  
Martijn Leijdekkers

There is some evidence that sugar beet root tissue strength affects damage susceptibility and storage losses. This study aimed at analyzing the effect of N application and of irrigation on tissue strength of sugar beet varieties, on root composition, and on root tip breakage and storage losses. For this purpose, field trials in six replicates with three sugar beet varieties were carried out with three N doses in The Netherlands and Belgium in 2018 and 2019, alternatively with three irrigation treatments in Sweden in 2018 and 2019. Results show a low impact of N application and irrigation on puncture resistance, tissue firmness and compressive strength of the roots, while varieties differed always stronger and significantly. Cell wall composition (pectin, hemicellulose, cellulose, lignin) did not differ markedly in roots from different environments (sites, years) and varieties, giving no explanation for differences in tissue strength. However, the percentage of cell wall material (AIR, marc) and of dry matter were higher in roots with higher tissue strength. Root tip breakage and sugar losses during storage tended to be lower when root compressive strength of varieties was higher. Hence, root tissue strength could serve as an indirect selection criterion for reduced damage susceptibility and improved storability of sugar beet varieties.


2021 ◽  
Author(s):  
Chandran Rajesh ◽  
Senthamarai Kannan Balaji ◽  
Prakash Ramesh ◽  
Narayanan Selvapalam ◽  
Karuppaiah Palanichelvam

Abstract To identify antimitotic compounds from abundant and inexpensive plant resources, banana pseudo-stem was (BPS) chosen. Onion root tip assay and earthworm regeneration assay were carried out to test theantimitotic potential of aqueous extract of BPS.Earthworm (Eudrilus eugeniae) regeneration assay exploits the regeneration ability of amputated earthworms that retain the clitellum region. Aqueous extract of BPS decreased the mitotic index in Allium cepa root tips. Besides, thisaqueous extract of BPS inhibited the regeneration of blastema from amputated earthworms as well. Validation of this extract with MTT (3-(4,5-dimethyl thiazolyl-2-yl)- 2,5-diphenyltetrazolium bromide) assay using MCF-7 breast cancer cell linefurther supported the presence of antimitotic compounds. Aqueous BPS extract was further fractionated with ethyl acetateand it was found to inhibit the regeneration of new tissues from amputated earthworms. Liquid Chromatography and Mass spectrometry (LC-MS) analysis was performed with aqueousBPS extract to predict the lead compounds.Prediction analysis with mass values revealed the presence of three different compounds viz. α-tocotrienol, 1,2,4-nonadecanetriol and 3',4',7-trihydroxyisoflavone, which were already reported to inhibit the cell division. All our results strongly supported that banana pseudo-stem extract possesses antimitotic compounds. This is the first report of identification of putative antimitotic compounds from aqueous extract of Musa paradisiaca var. Robusta by using earthworms.


Author(s):  
Ľubica Liptáková ◽  
Loriana Demecsová ◽  
Katarína Valentovičová ◽  
Veronika Zelinová ◽  
Ladislav Tamás

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