Bioactive l-DOPA induced quinoprotein formation to inhibit root growth of cucumber seedlings

It has been previously reported that POST-applied isoxaben can effectively control established hairy bittercress. Experiments were conducted to determine the relative importance of root vs. foliar entry of POST-applied isoxaben. At a common isoxaben rate of 0.56 kg/ha, foliar-only and foliar plus soil applications provided 10.5 and 23.3% control, respectively, as determined by fresh weight reduction. In contrast, soil-only application provided 47.0% control. Hairy bittercress foliar absorption of14C–isoxaben did not exceed 15% of the amount applied after 72 h. Therefore, the comparatively less effectiveness of foliar-only applications may be attributed primarily to limited absorption. Minimal isoxaben concentration required to inhibit root growth of hydroponically grown hairy bittercress was 0.0025 mg/L. Higher concentrations were required to produce a response in the foliage. Sorption of isoxaben by pine bark rooting substrate, typical of what is used in container nursery production, exceeded 99% of amount applied after 36 h. Even with 99% sorption, the probable concentration within the aqueous phase remains sufficient to inhibit hairy bittercress root growth. Additional studies with14C–isoxaben established that approximately 35% of the root-absorbed isoxaben was translocated into the foliage. Translocation from the roots into the foliage was reduced to 16% when the experiment was repeated during environmental conditions less favorable for vegetative growth (i.e., longer day length and higher temperature). Results indicate that the control of hairy bittercress with POST-applied isoxaben is likely the result of root absorption and root-growth inhibition. Expression of phytotoxicity within the foliage is also a component, but is dependent upon the root-absorbed isoxaben being translocated into the foliage. Extent of this translocation is dependent upon plant maturity and prevalent environmental conditions.

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Influence of UV‐B radiation and putrescine on shoot and root growth of cucumber seedlings grown in nutrient solution

Journal of Plant Nutrition ◽

10.1080/01904169709365281 ◽

1997 ◽

Vol 20 (6) ◽

pp. 613-623 ◽

Cited By ~ 4

Author(s):

Donald T. Krizek ◽

George F. Kramer ◽

Roman M. Mirecki

Keyword(s):

Root Growth ◽

Nutrient Solution ◽

Cucumber Seedlings ◽

Shoot And Root Growth

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Effect of Naptalam on Chloramben Toxicity, Uptake, Translocation, and Metabolism in Cucumber (Cucumis sativus)

Weed Science ◽

10.1017/s0043174500057817 ◽

1991 ◽

Vol 39 (1) ◽

pp. 27-32

Author(s):

Larry D. Knerr ◽

Herbert J. Hopen ◽

Nelson E. Balke

Keyword(s):

Root Growth ◽

Cucumis Sativus ◽

Shoot Growth ◽

Petri Dish ◽

Dry Weight ◽

Laboratory Studies ◽

Cucumber Seedlings ◽

Plant Parts ◽

Cucumber Roots ◽

Hydroponically Grown

Laboratory studies demonstrated that naptalam safens cucumber against the phytotoxic effects of chloramben. In petri dish studies, cucumber seedlings grown from seeds exposed to chloramben plus naptalam had greater shoot growth, root growth, and dry weight than seedlings grown from seeds exposed to chloramben alone. Naptalam also partially reversed the reduction in dry weight of various plant parts caused by exposure of roots of hydroponically grown seedlings to chloramben. More radioactivity from root-applied14C-chloramben remained in cucumber roots and less was translocated to shoots with a14C-chloramben plus naptalam treatment than with a14C-chloramben alone treatment. Naptalam appeared to influence chloramben metabolism. In various plant parts, concentrations of chloramben and its metabolites differed between the two treatments.

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A chemical genetic screen reveals that iminosugar inhibitors of plant glucosylceramide synthase inhibit root growth in Arabidopsis and cereals

Scientific Reports ◽

10.1038/s41598-018-34749-1 ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 2

Author(s):

Michael D. Rugen ◽

Mathieu M. J. L. Vernet ◽

Laila Hantouti ◽

Amalia Soenens ◽

Vasilios M. E. Andriotis ◽

...

Keyword(s):

Root Growth ◽

Genetic Screen ◽

Glucosylceramide Synthase ◽

Chemical Genetic ◽

Inhibit Root Growth

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Ammonium affects cell viability to inhibit root growth in Arabidopsis

Journal of Zhejiang University SCIENCE B ◽

10.1631/jzus.b1000335 ◽

2011 ◽

Vol 12 (6) ◽

pp. 477-484 ◽

Cited By ~ 9

Author(s):

Cheng Qin ◽

Ke-ke Yi ◽

Ping Wu

Keyword(s):

Root Growth ◽

Cell Viability ◽

Inhibit Root Growth

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Perspectives on Discovery of Microbial Phytotoxins with Herbicidal Activity

Weed Technology ◽

10.1017/s0890037x00032395 ◽

1988 ◽

Vol 2 (4) ◽

pp. 525-532 ◽

Cited By ~ 16

Author(s):

Horace G. Cutler

Keyword(s):

Natural Products ◽

Root Growth ◽

Specific Activity ◽

High Specific Activity ◽

Herbicidal Activity ◽

Biologically Active ◽

Natural State ◽

Natural Herbicides ◽

Synthetic Derivative ◽

Inhibit Root Growth

Biologically active natural products of microbial origin are attractive candidates for possible use in agriculture. They may be obtained by fermentation, used in their natural state, or subjected to synthetic modification for specific uses. These natural products are characterized by high specific activity and high selectivity, and they are biodegradable. The structures are extremely diverse and represent many classes of compounds ranging from very complex to simple. Cyclocarbamide A and B, fromStreptoverticilliumsp., have marked preemergence herbicidal activity. Nigerazine A and B, fromAspergillus nigervan Tieghem, also inhibit root growth in certain plants. Citreoviridin, fromPenicillium charlesiiSmith, preferentially controls the growth of monocotyledonous plants, as does a synthetic derivative of cladosporin, fromAspergillus repensDeBary, which bleaches chloroplasts. The 12-membered fungal macrolides (macrocyclic lactones) also inhibit root growth in many test plants and offer templates for further synthetic work. Herbicidins, fromStreptomyces saganonensis, are particularly effective against barnyardgrass, goosegrass, tufted mannagrass, and green panicum.Alternaria eichorniaeNag Raj et Ponnappa produces a toxin that is active against waterhyacinth and represents one of the more exotic structures. The macrocyclic trichothecenes are a significant class of natural products that tend to concentrate against a gradient in seeds of certain plants, which resist these microbially derived metabolites thereby producing seed with “built-in” natural herbicides.

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DNA damage inhibits root growth by enhancing cytokinin biosynthesis in Arabidopsis thaliana

10.1101/2020.06.19.160838 ◽

2020 ◽

Author(s):

Naoki Takahashi ◽

Soichi Inagaki ◽

Kohei Nishimura ◽

Hitoshi Sakakibara ◽

Ioanna Antoniadi ◽

...

Keyword(s):

Dna Damage ◽

Root Growth ◽

Plant Root ◽

Root Tip ◽

Dna Double Strand Breaks ◽

Cytokinin Biosynthesis ◽

Strand Breaks ◽

Dna Damage Signaling ◽

Expression Of Genes ◽

Inhibit Root Growth

AbstractPlant root growth is influenced by external factors to adapt to changing environmental conditions. However, the mechanisms by which environmental stresses affect root growth remain elusive. Here we found that DNA double-strand breaks (DSBs) induce the expression of genes for the synthesis of cytokinin hormones and enhance the accumulation of cytokinins in the Arabidopsis root tip. This is a programmed response to DSBs through the DNA damage signaling pathway. Our data showed that activation of cytokinin signalling suppresses the expression of PIN-FORMED genes that encode efflux carriers of another plant hormone, auxin, thereby disturbing downward auxin flow and causing cell cycle retardation in the G2 phase. Elevated cytokinin signalling also promotes an early transition from cell division to endoreplication, resulting in a reduction of the root meristem size. We propose that in response to DNA stress, plants inhibit root growth by orchestrating hormone biosynthesis and signalling.

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Inhibition of Downy Brome (Bromus tectorum) Root Growth by a Phytotoxin fromPseudomonas fluorescensStrain D7

Weed Technology ◽

10.1017/s0890037x00037003 ◽

1993 ◽

Vol 7 (1) ◽

pp. 134-139 ◽

Cited By ~ 29

Author(s):

Patrick J. Tranel ◽

David R. Gealy ◽

Ann C. Kennedy

Keyword(s):

Root Growth ◽

Root Elongation ◽

Bromus Tectorum ◽

Downy Brome ◽

Hydroponic System ◽

Crude Preparation ◽

Inhibit Root Growth ◽

Petri Plate ◽

Inhibition Of Root Elongation ◽

Plate System

Field applications of the rhizobacterium,Pseudomonas fluorescensstrain D7 (D7), have selectively suppressed downy brome in winter wheat test plots. A phytotoxin produced by D7 inhibits downy brome root growth. An assay system was developed for future investigations of the mechanism of action of this and other phytotoxins that inhibit root growth. A crude preparation of the phytotoxin, cell-free supernatant (CFS), had little activity on downy brome root elongation in a sand-petri plate system. CFS was very active in a hydroponic system, in which a 6% (v/v) concentration inhibited root elongation within 1.5 h. Inhibition of root elongation was reversible in this system. Root elongation of downy brome seedlings resumed within 3 h after removal from a 9-h incubation in 8% CFS. CFS from genetic variants of D7 did not substantially inhibit root growth and a semi-crystallized precipitation product from D7 CFS inhibited root growth similarly to D7 CFS, indicating that the phytotoxin present in the CFS was responsible for growth inhibition.

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Physiological Factors Affecting Response of Mature `Valencia' Orange Fruit to CMN-Pyrazole. I. Effects of Young Fruit, Shoot, and Root Growth

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.126.4.414 ◽

2001 ◽

Vol 126 (4) ◽

pp. 414-419 ◽

Cited By ~ 3

Author(s):

Rongcai Yuan ◽

Ulrich Hartmond ◽

Angela Grant ◽

Walter J. Kender

Keyword(s):

Root Growth ◽

Ethylene Production ◽

Shoot Growth ◽

Mature Fruit ◽

Physiological Factors ◽

Factors Affecting ◽

Young Fruit ◽

Valencia Orange ◽

Shoot And Root Growth ◽

Inhibit Root Growth

Influence of young fruit, shoot, and root growth on response of mature `Valencia' oranges [Citrus sinensis (L.) Osbeck] to the abscission chemical CMN-pyrazole was examined in 1999 and 2000. CMN-pyrazole dramatically increased ethylene production in mature fruit and reduced the fruit detachment force (FDF), except during a period of reduced response to CMN-pyrazole in early May when spring vegetative growth, young fruit of the following year's crop, and mature fruit were all on the trees. Removal of spring flushes, which included spring vegetative shoots and leafy and leafless inflorescences, prevented any young fruit and shoot growth, but did not inhibit root growth. However, trunk girdling in combination with removal of spring flushes not only prevented growth of young fruit and shoots but also inhibited root growth. During the responsive period, there were no differences in either ethylene production or FDF of CMN-pyrazole-treated mature oranges between 1) the nonmanipulated trees and those manipulated by either 2) removal of spring flushes alone, or 3) in combination with trunk girdling. However, during the less responsive period, ethylene production in CMN-pyrazole-treated mature oranges was significantly lower while the FDF was higher in nonmanipulated trees than in trees treated by either removal of spring flushes alone, or in combination with trunk girdling. There was no difference in either fruit ethylene production or FDF between trees manipulated by (2) removal of spring flushes alone, and (3) removal of spring flushes in combination with trunk girdling regardless of CMN-pyrazole application. Shoot growth terminated at least 2 weeks before the onset of the less responsive period. Removal of young fruit increased response of mature fruit to CMN-pyrazole during the less responsive period. This suggests that hormones from rapidly growing young fruit may be responsible for the occurrence of the less responsive period. Chemical name used: 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-pyrazole).

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