植物生态学报 ›› 2023, Vol. 47 ›› Issue (3): 331-347.DOI: 10.17521/cjpe.2021.0452

所属专题: 光合作用

• 研究论文 • 上一篇    下一篇

阴生植物三七稳态和动态光合特性对氮水平的响应

张金燕, 寸竹, 双升普, 洪杰, 孟珍贵, 陈军文()   

  1. 云南农业大学西南中药材种质创新与利用国家地方联合工程研究中心, 云南农业大学云南省药用植物生物学重点实验室, 云南农业大学农学与生物技术学院, 昆明 650201
  • 收稿日期:2021-12-06 接受日期:2022-05-20 出版日期:2023-03-20 发布日期:2023-02-28
  • 通讯作者: 陈军文
  • 作者简介:* (cjw31412@163.com)
  • 基金资助:
    国家自然科学基金(32160105);国家自然科学基金(81860676);云南省科技重大专项(202102AA310048)

Steady-state and dynamic photosynthetic characteristics of shade-tolerant species Panax notoginseng in response to nitrogen levels

ZHANG Jin-Yan, CUN Zhu, SHUANG Sheng-Pu, HONG Jie, MENG Zhen-Gui, CHEN Jun-Wen()   

  1. National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Key Laboratory of Medicinal Plant Biology of Yunnan Province, College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China
  • Received:2021-12-06 Accepted:2022-05-20 Online:2023-03-20 Published:2023-02-28
  • Contact: CHEN Jun-Wen
  • Supported by:
    National Natural Science Foundation of China(32160105);National Natural Science Foundation of China(81860676);Key Science and Technology Project of Yunnan Province(202102AA310048)

摘要:

氮(N)对植物光合作用至关重要。阴生植物在自然生长条件下, 接受的是高度动态的光照。然而, 探讨N水平对阴生植物动态光照下的光合调控作用的研究相对较少。为了阐明N对阴生植物动态光合作用的调控机制, 该研究以典型阴生植物三七(Panax notoginseng)为材料, 设置了低氮(LN, 112.5 kg·hm-2)和高氮(HN, 450.0 kg·hm-2) 2个N水平, 研究动态光和稳态光条件下植株叶片的光合气体交换参数及卡尔文循环酶蛋白的活性和数量。结果表明单位叶面积氮含量(Narea)与光照60 s的诱导状态(IS60)负相关, 与达到光合作用稳态90%所需的时间(tP90)和达到光合作用稳态100%所需的时间(tP-steady)正相关, 表明Narea并不是通过影响核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)的总活性来调控光诱导反应。短时间的低光间隔对Rubisco活性影响不显著, 但明显降低了果糖-1,6-二磷酸酶(FBPase)和景天庚酮糖-1,7-二磷酸酶(SBPase)的活性; 当高光照光斑突然出现时, Rubisco活性不受影响, 但是SBPase和FBPase需要被重新激活以匹配Rubisco的活性。因此, 低光间隔后的光合诱导主要受限于SBPase和FBPase的再激活。此外, HN处理叶片中Rubisco蛋白的含量高于FBPase和SBPase的含量; 在动态光的高光照阶段, HN处理叶片需要激活较高比例的FBPase和SBPase及较长的时间来恢复光合速率。该研究结果揭示: 动态光条件下, LN处理能缓解光诱导速率的下降, HN处理反而加剧光诱导速率的下降。核酮糖-1,5-二磷酸(RuBP)再生相关酶的限制可能是动态光条件下, HN处理加剧光诱导效率下降的原因之一。

关键词: 阴生植物, 动态光, 光诱导, 低氮, 高氮, 三七

Abstract:

Aims Nitrogen (N) is essential for the photosynthesis of plants. Shade plants are mostly exposed to dynamic light under natural growth conditions. However, little is known about the role of N levels in the photosynthetic regulation of shade plants under dynamic light. The objective of present study was to elucidate the mechanisms involved in the effect of N on dynamic photosynthesis in the typically shade-tolerant species Panax notoginseng.

Methods The gas exchange parameters and the activity and amount of Calvin cycle enzyme/proteins were examined under dynamic and steady light conditions in P. notoginseng grown under low N (LN, 112.5 kg·hm-2) and high N (HN, 450.0 kg·hm-2), respectively.

Important findings N content per unit of leaf area (Narea) was negatively correlated with the induction state at 60s of light (IS60) and positively correlated with the time required to reach 90% of photosynthetic steady state (tP90) and 100% of photosynthetic steady state (tP-steady), suggesting that Narea does not regulate the photosynthetic induction during dynamic light by the total activity of ribulose-1,5-bisphosphate carboxylase (Rubisco). Moreover, a short low light interval only slightly decreased the activity of Rubisco, but significantly reduced the activity of fructose-1,6-bisphosphatase (FBPase) and sedoheptulose-1,7-bisphosphatase (SBPase); when the sunfleck of high intensity appeared suddenly, Rubisco was still highly active, but SBPase and FBPase need to be reactivated to match Rubisco activity, so that photosynthetic induction after low light intervals is largely limited by reactivation of SBPase and FBPase. Furthermore, the content of Rubisco was higher than that of FBPase and SBPase. During the high light period of dynamic light, HN leaves need to activate a higher proportion of FBPase and SBPase and a longer period of time to resume photosynthesis. The results of present study reveal that under dynamic light condition, LN could alleviate the decline of photosynthetic induction rate, while HN exacerbated the decline of photosynthetic induction rate. The limitation in enzymes related to the ribulose-1,5-disphosphate (RuBP) may be one of the reasons why HN exacerbates the decline of photosynthetic induction rate under dynamic light condition.

Key words: shade-tolerant species, dynamic light, photoinduction, low nitrogen, high nitrogen, Panax notoginseng