Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize Ears
The border row crop in strip intercropped maize is often exposed to heterogeneous light conditions, resulting in increased photosynthesis and yield decreased. Previous studies have focused on photosynthetic productivity, whereas carbon allocation could also be one of the major causes of decreased yi...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-08-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/9/8/987 |
| _version_ | 1797560364896878592 |
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| author | Guopeng Chen Hong Chen Kai Shi Muhammad Ali Raza George Bawa Xin Sun Tian Pu Taiwen Yong Weiguo Liu Jiang Liu Junbo Du Feng Yang Wenyu Yang Xiaochun Wang |
| author_facet | Guopeng Chen Hong Chen Kai Shi Muhammad Ali Raza George Bawa Xin Sun Tian Pu Taiwen Yong Weiguo Liu Jiang Liu Junbo Du Feng Yang Wenyu Yang Xiaochun Wang |
| author_sort | Guopeng Chen |
| collection | DOAJ |
| description | The border row crop in strip intercropped maize is often exposed to heterogeneous light conditions, resulting in increased photosynthesis and yield decreased. Previous studies have focused on photosynthetic productivity, whereas carbon allocation could also be one of the major causes of decreased yield. However, carbon distribution remains unclear in partially shaded conditions. In the present study, we applied heterogeneous light conditions (T), and one side of plants was shaded (T-30%), keeping the other side fully exposed to light (T-100%), as compared to control plants that were exposed entirely to full-light (CK). Dry weight, carbon assimilation, <sup>13</sup>C abundance, and transport tissue structure were analyzed to clarify the carbon distribution in partial shading of plants. T caused a marked decline in dry weight and harvest index (HI), whereas dry weight in unshaded and shaded leaves did not differ. Net photosynthesis rate (Pn), the activity of sucrose phosphate synthase enzymes (SPS), and sucrose concentration increased in unshaded leaves. Appropriately, 5.7% of the <sup>13</sup>C from unshaded leaves was transferred to shaded leaves. Furthermore, plasmodesma density in the unshaded (T-100%) and shaded (T-30%) leaves in T was not significantly different but was lower than that of CK. Similarly, the vascular bundle total area of T was decreased. <sup>13</sup>C transfer from unshaded leaves to ear in T was decreased by 18.0% compared with that in CK. Moreover, <sup>13</sup>C and sucrose concentration of stem in T were higher than those in CK. Our results suggested that, under heterogeneous light, shaded leaves as a sink imported the carbohydrates from the unshaded leaves. Ear and shaded leaf competed for carbohydrates, and were not conducive to tissue structure of sucrose transport, resulting in a decrease in the carbon proportion in the ear, harvest index, and ear weight. |
| first_indexed | 2024-03-10T17:59:03Z |
| format | Article |
| id | doaj.art-f9380babd4c74b5a893034b0a6d2a9d7 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-10T17:59:03Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-f9380babd4c74b5a893034b0a6d2a9d72023-11-20T09:03:28ZengMDPI AGPlants2223-77472020-08-019898710.3390/plants9080987Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize EarsGuopeng Chen0Hong Chen1Kai Shi2Muhammad Ali Raza3George Bawa4Xin Sun5Tian Pu6Taiwen Yong7Weiguo Liu8Jiang Liu9Junbo Du10Feng Yang11Wenyu Yang12Xiaochun Wang13College of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaCollege of Agronomy, Sichuan Agricultural University, Chengdu 611130, ChinaThe border row crop in strip intercropped maize is often exposed to heterogeneous light conditions, resulting in increased photosynthesis and yield decreased. Previous studies have focused on photosynthetic productivity, whereas carbon allocation could also be one of the major causes of decreased yield. However, carbon distribution remains unclear in partially shaded conditions. In the present study, we applied heterogeneous light conditions (T), and one side of plants was shaded (T-30%), keeping the other side fully exposed to light (T-100%), as compared to control plants that were exposed entirely to full-light (CK). Dry weight, carbon assimilation, <sup>13</sup>C abundance, and transport tissue structure were analyzed to clarify the carbon distribution in partial shading of plants. T caused a marked decline in dry weight and harvest index (HI), whereas dry weight in unshaded and shaded leaves did not differ. Net photosynthesis rate (Pn), the activity of sucrose phosphate synthase enzymes (SPS), and sucrose concentration increased in unshaded leaves. Appropriately, 5.7% of the <sup>13</sup>C from unshaded leaves was transferred to shaded leaves. Furthermore, plasmodesma density in the unshaded (T-100%) and shaded (T-30%) leaves in T was not significantly different but was lower than that of CK. Similarly, the vascular bundle total area of T was decreased. <sup>13</sup>C transfer from unshaded leaves to ear in T was decreased by 18.0% compared with that in CK. Moreover, <sup>13</sup>C and sucrose concentration of stem in T were higher than those in CK. Our results suggested that, under heterogeneous light, shaded leaves as a sink imported the carbohydrates from the unshaded leaves. Ear and shaded leaf competed for carbohydrates, and were not conducive to tissue structure of sucrose transport, resulting in a decrease in the carbon proportion in the ear, harvest index, and ear weight.https://www.mdpi.com/2223-7747/9/8/987carbon partitioningleaf plasmodesmataphotosynthesissinkshade |
| spellingShingle | Guopeng Chen Hong Chen Kai Shi Muhammad Ali Raza George Bawa Xin Sun Tian Pu Taiwen Yong Weiguo Liu Jiang Liu Junbo Du Feng Yang Wenyu Yang Xiaochun Wang Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize Ears Plants carbon partitioning leaf plasmodesmata photosynthesis sink shade |
| title | Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize Ears |
| title_full | Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize Ears |
| title_fullStr | Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize Ears |
| title_full_unstemmed | Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize Ears |
| title_short | Heterogeneous Light Conditions Reduce the Assimilate Translocation Towards Maize Ears |
| title_sort | heterogeneous light conditions reduce the assimilate translocation towards maize ears |
| topic | carbon partitioning leaf plasmodesmata photosynthesis sink shade |
| url | https://www.mdpi.com/2223-7747/9/8/987 |
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