Xu Xiaohan, Tian Zhiqiang, Xing Anqi, Wu Zichen, Li Xuyan, Dai Lingcong, Yang Yiyang, Yin Juan, Wang Yuhua
College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
Institute of Leisure Agriculture, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Plants (Basel). 2022 Aug 29;11(17):2233. doi: 10.3390/plants11172233.
Nitric oxide (NO), as a signal molecule, is involved in the mediation of heavy-metal-stress-induced physiological responses in plants. In this study, we investigated the effect of NO on pollen tubes exposed to aluminum (Al) stress. Exogenous application of the NO donor decreased the pollen germination rate and pollen tube length and increased the malondialdehyde (MDA) content and antioxidant enzyme activities under Al stress. Simultaneously, the NO donor effectively increased NO content in pollen tube of under Al stress and could aggravate the damage of Al to pollen tubes by promoting the uptake of Al. In addition, application of the NO-specific scavenger significantly alleviated stress damage in pollen tube under Al stress. Moreover, 18 members from a key Al-transporting gene family were identified, which could be divided into four subclasses. Pearson correlation analysis showed the expression level of showed significant positive correlation with the Al concentration gradient and NO levels, but a significant negative correlation with pollen germination rate and pollen tube length. The expression level of was negatively correlated with the Al concentration gradient and NO level, and positively correlated with pollen germination rate and pollen tube length. The expression level of showed a significant negative correlation with Al concentration and NO content in pollen tubes, but significant positive correlation with pollen germination rate and pollen tube length. In conclusion, a complex signal network regulated by NO-mediated revealed that was regulated by environmental Al and NO to assist Al entry into pollen tubes; might be influenced by the Al signal, stimulate malate efflux in vacuoles and chelate with Al to detoxify Al in pollen tube.
一氧化氮（NO）作为一种信号分子，参与介导植物中重金属胁迫诱导的生理反应。在本研究中，我们研究了NO对暴露于铝（Al）胁迫下的花粉管的影响。在Al胁迫下，外源施加NO供体降低了花粉萌发率和花粉管长度，增加了丙二醛（MDA）含量和抗氧化酶活性。同时，NO供体有效增加了Al胁迫下花粉管中的NO含量，并通过促进Al的吸收加剧了Al对花粉管的损伤。此外，应用NO特异性清除剂显著减轻了Al胁迫下花粉管的胁迫损伤。此外，鉴定了一个关键Al转运基因家族的18个成员，可分为四个亚类。Pearson相关性分析表明，其表达水平与Al浓度梯度和NO水平呈显著正相关，但与花粉萌发率和花粉管长度呈显著负相关。的表达水平与Al浓度梯度和NO水平呈负相关，与花粉萌发率和花粉管长度呈正相关。的表达水平与花粉管中的Al浓度和NO含量呈显著负相关，但与花粉萌发率和花粉管长度呈显著正相关。总之，由NO介导的复杂信号网络表明，受环境Al和NO调控，协助Al进入花粉管；可能受Al信号影响，刺激液泡中苹果酸外流并与Al螯合，以解除花粉管中Al的毒性。
