Shao Xingyuan, Yu Pengyue, Zuo Min, Tong Zhenglong, Huang Zhi, Xie Zhiyan, Chang Ruimin, Peng Jianwei, Deng Yaocheng, Huang Ying
National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources, Hunan Agricultural University, Changsha, 410128, China.
Xiangyin Agri-Tech and Agricultural Machinery Technology Promotion Service Center, Xiangyin, 414600, China.
J Plant Physiol. 2025 Aug;311:154540. doi: 10.1016/j.jplph.2025.154540. Epub 2025 Jun 4.
This study aimed to investigate the influence of the morphological traits of rice leaves (stomata, leaf area, and trichome density) on the accumulation of heavy metals in rice grains. It also screens for varieties with low heavy metal accumulation and high adaptability (less foliar uptake). Field trials on 37 rice varieties and pot trials regulated by abscisic acid (ABA) were conducted to explore the effects of various leaf surface morphologies and stomata on cadmium (Cd) accumulation in brown rice. Analyzing leaf morphology in different rice varieties revealed that five with high Cd content had an 8.92 %-38.49 % increase in stomatal pore area compared to the average. Meanwhile, these five rice varieties with high Cd content exhibited xylem Cd transit rates above average, ranging from 9.22 % to 182.58 %. Transporter factors throughout the rice plant indicated that the processes from stem-leaf to rachis and husk to brown rice are crucial for Cd accumulation in rice. The results of the correlation and structural equation modelling indicated a significant correlation between rice leaf stomata and the transit rate of Cd in rice xylem. ABA spraying experiments showed that stomata regulate rice transpiration and affect Cd transport and accumulation in rice. Results showed that ABA spraying significantly reduced Cd content in brown rice by 2.4 %-24 % and transpiration rate (33.17 %-54.45 %). Ultimately, the variety ZhuLiangYou 35, characterized by its smaller stomatal pore area and reduced heavy metal concentration in brown rice, is recommended as an appropriate choice.
本研究旨在探讨水稻叶片形态特征（气孔、叶面积和表皮毛密度）对水稻籽粒中重金属积累的影响。同时筛选出重金属积累量低且适应性强（叶面吸收少）的品种。通过对37个水稻品种进行田间试验以及用脱落酸（ABA）调控的盆栽试验，来探究不同叶片表面形态和气孔对糙米中镉（Cd）积累的影响。对不同水稻品种的叶片形态进行分析发现，与平均水平相比，镉含量高的5个品种的气孔面积增加了8.92% - 38.49%。同时，这5个镉含量高的水稻品种的木质部镉转运率高于平均水平，范围在9.22%至182.58%之间。对水稻全株转运因子的研究表明，从茎叶到穗轴以及从稻壳到糙米的过程对水稻中镉的积累至关重要。相关性和结构方程模型的结果表明，水稻叶片气孔与水稻木质部中镉的转运率之间存在显著相关性。ABA喷施试验表明，气孔调节水稻蒸腾作用，并影响水稻中镉的运输和积累。结果表明，喷施ABA显著降低了糙米中的镉含量2.4% - 24%以及蒸腾速率（33.17% - 54.45%）。最终，推荐气孔面积较小且糙米中重金属浓度降低的品种株两优35作为合适的选择。
