RNAi-mediated suppression of isoprene emission in poplar transiently impacts phenolic metabolism under high temperature and high light intensities: a transcriptomic and metabolomic analysis

Corn(Zea maysL.) in the two to three-leaf stage grown 18 to 21 days in a growth chamber under cold, wet conditions was injured by postemergence application of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) plus emulsifiable phytobland oil. Injury was most severe when these plants were kept under cold, wet conditions for 48 hr after the herbicidal spray was applied, followed by exposure to high light intensity and high temperature. Under these growth chamber conditions, approximately 50% of the atrazine-treated plants died. Since wet foliage before and after application increased foliar penetration and low temperature decreased the rate of detoxication to peptide conjugates, atrazine accumulated under cold, wet conditions. This accumulation of foliarly-absorbed atrazine and the “weakened” conditions of the plants grown under the stress conditions is believed to be responsible for the injury to corn. Hydroxylation and the dihydroxybenzoxazin-3-one content in the roots were reduced at low temperature, but it is unlikely that this contributed to the death of the corn.

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THE INFLUENCE OF TEMPERATURE AND SOIL MOISTURE ON THE PHYTOTOXICITY OF DICAMBA, PICLORAM, BROMOXYNIL, AND 2,4-D ESTER

Canadian Journal of Plant Science ◽

10.4141/cjps66-109 ◽

1966 ◽

Vol 46 (6) ◽

pp. 653-660 ◽

Cited By ~ 9

Author(s):

H. A. Friesen ◽

D. A. Dew

Keyword(s):

Soil Moisture ◽

High Temperature ◽

High Light Intensity ◽

High Light ◽

Test Plant ◽

Optimum Growth ◽

Limited Growth ◽

Fagopyrum Tataricum ◽

Influence Of Temperature ◽

Reduced Activity

Moisture and temperature differentially affected the phytotoxicity of four herbicides to tartary buckwheat, Fagopyrum tataricum (L.) Gaertn., the test plant. The activity of the systemic herbicides 2,4-D, dicamba, and picloram was greatest when conditions of soil moisture and air temperature tended toward optimum growth of the buckwheat. When moisture limited growth the phytotoxicity of these three herbicides was significantly less. Reducing the temperature from the optimum 24°–13 °C to 18°–7 °C did not significantly reduce the activity of these herbicides. Conversely, the phytotoxicity of the contact herbicide bromoxynil was significantly greater at the low rather than the high temperature program. This activity was accentuated when moisture was also made limiting but its effect was less pronounced. High light intensity tended to result in abnormal buckwheat growth and reduced activity of the herbicides.

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On Detrimental Effects of High Light Intensities on the Photosynthetic Mechanism

Physiologia Plantarum ◽

10.1111/j.1399-3054.1952.tb07529.x ◽

1952 ◽

Vol 5 (3) ◽

pp. 334-344 ◽

Cited By ~ 34

Author(s):

E. Steemann Nielsen

Keyword(s):

High Light ◽

Light Intensities

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Source of 12C in Calvin–Benson cycle intermediates and isoprene emitted from plant leaves fed with 13CO2

Biochemical Journal ◽

10.1042/bcj20200480 ◽

2020 ◽

Vol 477 (17) ◽

pp. 3237-3252 ◽

Cited By ~ 2

Author(s):

Thomas D. Sharkey ◽

Alyssa L. Preiser ◽

Sarathi M. Weraduwage ◽

Linus Gog

Keyword(s):

High Temperature ◽

Carbon Sources ◽

Plant Leaves ◽

Isoprene Emission ◽

Variable Contribution ◽

Terpene Synthesis ◽

Glucose 6 Phosphate Dehydrogenase

Feeding 14CO2 was crucial to uncovering the path of carbon in photosynthesis. Feeding 13CO2 to photosynthesizing leaves emitting isoprene has been used to develop hypotheses about the sources of carbon for the methylerythritol 4-phosphate pathway, which makes the precursors for terpene synthesis in chloroplasts and bacteria. Both photosynthesis and isoprene studies found that products label very quickly (<10 min) up to 80–90% but the last 10–20% of labeling requires hours indicating a source of 12C during photosynthesis and isoprene emission. Furthermore, studies with isoprene showed that the proportion of slow label could vary significantly. This was interpreted as a variable contribution of carbon from sources other than the Calvin–Benson cycle (CBC) feeding the methylerythritol 4-phosphate pathway. Here, we measured the degree of label in isoprene and photosynthetic metabolites 20 min after beginning to feed 13CO2. Isoprene labeling was the same as labeling of photosynthesis intermediates. High temperature reduced the label in isoprene and photosynthesis intermediates by the same amount indicating no role for alternative carbon sources for isoprene. A model assuming glucose, fructose, and/or sucrose reenters the CBC as ribulose 5-phosphate through a cytosolic shunt involving glucose 6-phosphate dehydrogenase was consistent with the observations.

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Light intensity regulates phototaxis, foraging and righting behaviors of the sea urchin Strongylocentrotus intermedius

PeerJ ◽

10.7717/peerj.8001 ◽

2019 ◽

Vol 7 ◽

pp. e8001 ◽

Cited By ~ 4

Author(s):

Jiangnan Sun ◽

Xiaomei Chi ◽

Mingfang Yang ◽

Jingyun Ding ◽

Dongtao Shi ◽

...

Keyword(s):

Light Intensity ◽

Foraging Behavior ◽

Sea Urchins ◽

High Light Intensity ◽

High Light ◽

Strongylocentrotus Intermedius ◽

Low Light ◽

Low Light Intensity ◽

Light Intensities ◽

Significant Difference

Small sea urchins Strongylocentrotus intermedius (1–2 cm of test diameter) are exposed to different environments of light intensities after being reseeded to the sea bottom. With little information available about the behavioral responses of S. intermedius to different light intensities in the environment, we carried out an investigation on how S. intermedius is affected by three light intensity environments in terms of phototaxis, foraging and righting behaviors. They were no light (zero lx), low light intensity (24–209 lx) and high light intensity (252–2,280 lx). Light intensity had obvious different effects on phototaxis. In low light intensity, sea urchins moved more and spent significantly more time at the higher intensity (69–209 lx) (P = 0.046). S. intermedius in high light intensity, in contrast, spent significantly more time at lower intensity (252–690 lx) (P = 0.005). Unexpectedly, no significant difference of movement (average velocity and total distance covered) was found among the three light intensities (P > 0.05). Foraging behavior of S. intermedius was significantly different among the light intensities. In the no light environment, only three of ten S. intermedius found food within 7 min. In low light intensity, nine of 10 sea urchins showed successful foraging behavior to the food placed at 209 lx, which was significantly higher than the ratio of the number (two of 10) when food was placed at 24 lx (P = 0.005). In the high light intensity, in contrast, significantly less sea urchins (three of 10) found food placed at the higher light intensity (2,280 lx) compared with the lower light intensity (252 lx) (10/10, P = 0.003). Furthermore, S. intermedius showed significantly longer righting response time in the high light intensity compared with both no light (P = 0.001) and low light intensity (P = 0.031). No significant difference was found in righting behavior between no light and low light intensity (P = 0.892). The present study indicates that light intensity significantly affects phototaxis, foraging and righting behaviors of S. intermedius and that ~200 lx might be the appropriate light intensity for reseeding small S. intermedius.

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Stomatal aperture can compensate altered stomatal density in Arabidopsis thaliana at growth light conditions

Functional Plant Biology ◽

10.1071/fp06078 ◽

2006 ◽

Vol 33 (11) ◽

pp. 1037 ◽

Cited By ~ 54

Author(s):

Dirk Büssis ◽

Uritza von Groll ◽

Joachim Fisahn ◽

Thomas Altmann

Keyword(s):

Arabidopsis Thaliana ◽

Stomatal Conductance ◽

Stomatal Density ◽

Co2 Assimilation ◽

High Light ◽

Stomatal Aperture ◽

Photochemical Quenching ◽

Light Conditions ◽

Wild Type ◽

Light Intensities

Stomatal density of transgenic Arabidopsis thaliana plants over-expressing the SDD1 (stomatal density and distribution) gene was reduced to 40% and in the sdd1-1 mutant increased to 300% of the wild type. CO2 assimilation rate and stomatal conductance of over-expressers and the sdd1-1 mutant were unchanged compared with wild types when measured under the light conditions the plants were exposed to during growth. Lower stomatal density was compensated for by increased stomatal aperture and conversely, increased stomatal density was compensated for by reduced stomatal aperture. At high light intensities the assimilation rates and stomatal conductance of SDD1 over-expressers were reduced to 80% of those in wild type plants. Areas beneath stomata and patches lacking stomata were analysed separately. In areas without stomata, maximum fluorescence yield (Fv / Fm) and quantum yield of photosystem II (Φ PSII) were significantly lower than in areas beneath stomata. In areas beneath stomata, Fv / Fm and Φ PSII were identical to levels measured in wild type leaves. At high light intensities over-expressers showed decreased photochemical quenching (qP) compared with wild types. However, the decrease of qP was significantly stronger in areas without stomata than in mesophyll areas beneath stomata. At high CO2 partial pressures and high light intensities CO2 assimilation rates of SDD1 over-expressers did not reach wild type levels. These results indicate that photosynthesis in SDD1 over-expressers was reduced because of limiting CO2 in areas furthest from stomata at high light.

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