![Early acclimation changes in the photosynthetic apparatus of bean plants during short-term exposure to elevated CO"2 concentration under high ... Agriculture, Ecosystems and Environment]](https://www.ebooknetworking.net/books/B00/0RR/bigB000RR1PB4.jpg)
Early acclimation changes in the photosynthetic apparatus of bean plants during short-term exposure to elevated CO"2 concentration under high ... Agriculture, Ecosystems and Environment]
Description
This digital document is a journal article from Agriculture, Ecosystems and Environment, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
To follow the early response of the photosynthetic apparatus to elevated [CO"2] applied in combination with other stress factors we exposed 19-day-old bean plants (Phaseolus vulgaris L. cv. Cheren Starozagorski) for relatively short period (4 days, 8h per day) to different temperature, light and [CO"2] regimes: 23 or 39^oC air temperature, low (100@mmolm^-^2s^-^1 - LL) or high (1000@mmolm^-^2s^-^1 - HL) photosynthetic photon flux density (PPFD) and ambient (350@mmolmol^-^1) or elevated (1300@mmolmol^-^1) CO"2 concentration. Chlorophyll fluorescence kinetics and the response of assimilation rate to intercellular CO"2 concentration were registered during the 4-day period. At growth temperature (23^oC), we observed some stimulation of photosynthesis by elevated [CO"2], expressed by higher maximal net photosynthetic rate, carboxylation capacity and electron transport capacity, while at high temperature (39^oC) the effect of elevated [CO"2] on photosynthesis was negative, i.e. HT induced downward acclimation. The negative effect of the CO"2 enrichment at HT, expressed as diminished Rubisco activity and limitations in RuBP and P regeneration, may be due to starch accumulation as it was seen from the electron micrographs. Our results show that the ratio of intercellular to ambient [CO"2], which reflects the coupling between stomata and photosynthetic CO"2 assimilation, was unaffected by elevated [CO"2] as well as by changes in light and temperature. In the 4-day period, the PSII efficiency was not affected by the elevated [CO"2]. The fluorescence parameters were noticeably reduced at HL already on the first day and decreased further with time. We concluded that 4-day growth of plants in atmosphere with CO"2 concentration more than three times above the natural modifies the response of plants to light and temperature, which was connected with functional and structural changes.
Description:
To follow the early response of the photosynthetic apparatus to elevated [CO"2] applied in combination with other stress factors we exposed 19-day-old bean plants (Phaseolus vulgaris L. cv. Cheren Starozagorski) for relatively short period (4 days, 8h per day) to different temperature, light and [CO"2] regimes: 23 or 39^oC air temperature, low (100@mmolm^-^2s^-^1 - LL) or high (1000@mmolm^-^2s^-^1 - HL) photosynthetic photon flux density (PPFD) and ambient (350@mmolmol^-^1) or elevated (1300@mmolmol^-^1) CO"2 concentration. Chlorophyll fluorescence kinetics and the response of assimilation rate to intercellular CO"2 concentration were registered during the 4-day period. At growth temperature (23^oC), we observed some stimulation of photosynthesis by elevated [CO"2], expressed by higher maximal net photosynthetic rate, carboxylation capacity and electron transport capacity, while at high temperature (39^oC) the effect of elevated [CO"2] on photosynthesis was negative, i.e. HT induced downward acclimation. The negative effect of the CO"2 enrichment at HT, expressed as diminished Rubisco activity and limitations in RuBP and P regeneration, may be due to starch accumulation as it was seen from the electron micrographs. Our results show that the ratio of intercellular to ambient [CO"2], which reflects the coupling between stomata and photosynthetic CO"2 assimilation, was unaffected by elevated [CO"2] as well as by changes in light and temperature. In the 4-day period, the PSII efficiency was not affected by the elevated [CO"2]. The fluorescence parameters were noticeably reduced at HL already on the first day and decreased further with time. We concluded that 4-day growth of plants in atmosphere with CO"2 concentration more than three times above the natural modifies the response of plants to light and temperature, which was connected with functional and structural changes.
