Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leaves
Plants are exposed to high light intensity, high leaf temperatures and high air-to-leaf water vapor pressure deficit (ALVPD) during the day. These environmental stresses cause stomatal closure and photoinhibitory damage, leading to midday depression of photosynthesis. Chloroplast positioning is esse...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2020-04-01
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| Series: | Plant Production Science |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/1343943X.2019.1673666 |
| _version_ | 1819082475971805184 |
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| author | Eri Maai Kazusa Nishimura Rihito Takisawa Tetsuya Nakazaki |
| author_facet | Eri Maai Kazusa Nishimura Rihito Takisawa Tetsuya Nakazaki |
| author_sort | Eri Maai |
| collection | DOAJ |
| description | Plants are exposed to high light intensity, high leaf temperatures and high air-to-leaf water vapor pressure deficit (ALVPD) during the day. These environmental stresses cause stomatal closure and photoinhibitory damage, leading to midday depression of photosynthesis. Chloroplast positioning is essential for the efficient operation of photosynthesis. However, chloroplast behavior before, during, and even after the midday depression of photosynthesis remains unknown. We investigated changes in the intracellular positioning of chloroplasts and photosynthetic traits under a diurnal pattern of light. Sorghum leaves were exposed to a 12-h regime of light mimicking the natural light environment, with constant leaf temperature and ALVPD. Net photosynthetic rate (Pn) showed a diurnal pattern, and midday depression in Pn was observed at 3.8 h of irradiation. Depression in Pn was attributed to stomatal limitation because the decrease in Pn was in accordance with the decrease in stomatal conductance. The maximum efficiency of photosystem II decreased with the increase in light intensity and remained low after 12 h of irradiation. Bundle sheath chloroplasts swelled after 8 h of irradiation, representing the accumulation of starch. Conversely, mesophyll chloroplasts exhibited avoidance response after 4 h of irradiation, and the avoidance position was maintained during the remainder of the daytime. These data suggest that chloroplasts are subject to light stress during and after the midday depression of photosynthesis. The intensity of natural light is excessive for most of the day and this light stress induces chloroplast avoidance response and depression of photosynthesis. |
| first_indexed | 2024-12-21T20:17:16Z |
| format | Article |
| id | doaj.art-44c293e842cf46aaa5adc1f41332397f |
| institution | Directory Open Access Journal |
| issn | 1343-943X 1349-1008 |
| language | English |
| last_indexed | 2024-12-21T20:17:16Z |
| publishDate | 2020-04-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Plant Production Science |
| spelling | doaj.art-44c293e842cf46aaa5adc1f41332397f2022-12-21T18:51:34ZengTaylor & Francis GroupPlant Production Science1343-943X1349-10082020-04-0123217218110.1080/1343943X.2019.16736661673666Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leavesEri Maai0Kazusa Nishimura1Rihito Takisawa2Tetsuya Nakazaki3Kyoto UniversityKyoto UniversityKyoto UniversityKyoto UniversityPlants are exposed to high light intensity, high leaf temperatures and high air-to-leaf water vapor pressure deficit (ALVPD) during the day. These environmental stresses cause stomatal closure and photoinhibitory damage, leading to midday depression of photosynthesis. Chloroplast positioning is essential for the efficient operation of photosynthesis. However, chloroplast behavior before, during, and even after the midday depression of photosynthesis remains unknown. We investigated changes in the intracellular positioning of chloroplasts and photosynthetic traits under a diurnal pattern of light. Sorghum leaves were exposed to a 12-h regime of light mimicking the natural light environment, with constant leaf temperature and ALVPD. Net photosynthetic rate (Pn) showed a diurnal pattern, and midday depression in Pn was observed at 3.8 h of irradiation. Depression in Pn was attributed to stomatal limitation because the decrease in Pn was in accordance with the decrease in stomatal conductance. The maximum efficiency of photosystem II decreased with the increase in light intensity and remained low after 12 h of irradiation. Bundle sheath chloroplasts swelled after 8 h of irradiation, representing the accumulation of starch. Conversely, mesophyll chloroplasts exhibited avoidance response after 4 h of irradiation, and the avoidance position was maintained during the remainder of the daytime. These data suggest that chloroplasts are subject to light stress during and after the midday depression of photosynthesis. The intensity of natural light is excessive for most of the day and this light stress induces chloroplast avoidance response and depression of photosynthesis.http://dx.doi.org/10.1080/1343943X.2019.1673666chloroplast movementhigh lightmesophyllmidday depression of photosynthesisphotoinhibitionsorghum |
| spellingShingle | Eri Maai Kazusa Nishimura Rihito Takisawa Tetsuya Nakazaki Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leaves Plant Production Science chloroplast movement high light mesophyll midday depression of photosynthesis photoinhibition sorghum |
| title | Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leaves |
| title_full | Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leaves |
| title_fullStr | Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leaves |
| title_full_unstemmed | Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leaves |
| title_short | Light stress-induced chloroplast movement and midday depression of photosynthesis in sorghum leaves |
| title_sort | light stress induced chloroplast movement and midday depression of photosynthesis in sorghum leaves |
| topic | chloroplast movement high light mesophyll midday depression of photosynthesis photoinhibition sorghum |
| url | http://dx.doi.org/10.1080/1343943X.2019.1673666 |
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