Gao Bo, Hu Shaowu, Zhou Mingyuan, Jing Liquan, Wang Yunxia, Zhu Jianguo, Sun Xingxing, Wang Kai, Wang Yulong, Yang Lianxin
Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province, Yangzhou University, Yangzhou, Jiangsu, China.
Research Department for Agro-ecological Security, Jiangsu Coastal Area Institute of Agricultural Sciences, Yancheng, Jiangsu, China.
Front Plant Sci. 2024 Nov 18;15:1450893. doi: 10.3389/fpls.2024.1450893. eCollection 2024.
This study explores how elevated CO concentration may alter the source-sink dynamics in rice by providing additional carbon for photosynthesis, thereby affecting nutrient absorption and distribution.
A free-air CO enrichment experiment was conducted on a japonica cultivar Wuyunjing 27 in 2017 and 2018 growing seasons. The plants were exposed to ambient and elevated CO level (increased by 200 μmol·mol-1) and two source-sink manipulation treatments (control with no leaf cutting and cutting off the top three leaves at heading).
The elevated CO significantly increased the above-ground biomass and the straw non-structural carbohydrate concentration by an average of 19.3% and 12.5%, respectively. Significant changes in the concentrations of N, S, Fe, and Zn in straw were noted under elevated CO, with average decreases by 7.1, 7.2, 11.6, and 10.1%, respectively. The exposure to elevated CO significantly enhanced the elements accumulation, yet it had minimal impact on their distribution across different organs. When compared to intact rice, removing the top three leaves at heading reduced the above-ground biomass by 36.8% and the straw non-structural carbohydrate content by 44.8%. Leaf-cutting generally increased the concentration of elements in stem, leaf, and grain, likely due to a concentration effect from reduced biomass and carbohydrate accumulation. Leaf-cutting reduced element accumulation and shifted element allocation in rice organs. It increased the proportion of elements in stems while reduced their presence in leaves and grains.
Our study suggests that a dilution effect may cause a decrease in mineral elements concentrations under elevated CO because of the increase in biomass and carbohydrates.
本研究探讨了升高的二氧化碳浓度如何通过为光合作用提供额外的碳来改变水稻的源库动态，从而影响养分的吸收和分配。
在2017年和2018年生长季对粳稻品种武运粳27进行了开放式空气二氧化碳浓度增高实验。将植株暴露于环境二氧化碳浓度和升高的二氧化碳浓度（增加200μmol·mol-1）下，并进行两种源库调控处理（不剪叶对照和抽穗期剪掉顶部三片叶）。
升高的二氧化碳显著增加了地上部生物量和茎秆非结构性碳水化合物浓度，平均分别增加了19.3%和12.5%。在升高的二氧化碳浓度下，茎秆中氮、硫、铁和锌的浓度有显著变化，平均分别降低了7.1%、7.2%、11.6%和10.1%。暴露于升高的二氧化碳显著增强了元素积累，但对其在不同器官中的分配影响极小。与完整水稻相比，抽穗期剪掉顶部三片叶使地上部生物量降低了36.8%，茎秆非结构性碳水化合物含量降低了44.8%。剪叶通常会增加茎、叶和籽粒中元素的浓度，这可能是由于生物量和碳水化合物积累减少导致的浓缩效应。剪叶减少了水稻器官中元素的积累并改变了元素分配。它增加了茎中元素的比例，同时减少了叶和籽粒中元素的含量。
我们的研究表明，由于生物量和碳水化合物的增加，稀释效应可能导致在升高的二氧化碳浓度下矿质元素浓度降低。
