Scholarlink

Abstract <p>The evergreen shrub <i>Arctostaphylos uva-ursi</i> (L.) Spreng. is one of the most common species in the natural flora of Yakutia permafrost ecosystems. The analysis of the OJIP chlorophyll <i>a</i> fluorescence transient curves enabled the determination of adaptive changes in key JIP test parameters during cold hardening of plants under natural conditions. Long-term acclimation of PSII was accompanied by an increase in the relative amounts of Q<sub>B</sub>- and Q<sub>A</sub>-non-reducing centers. In addition, there was a limitation of photosynthetic electron transport activity (ET<sub>О</sub>/ABS), as well as a steady increase in the values of <i>F</i><sub>K</sub>/<i>F</i><sub>J</sub> parameter, which characterizes the extent of inactivation of the PSII donor side. In the range of average daily temperatures from +5°C to –10°C, an increase in the content of zeaxanthin (Z) fraction maintained throughout the day and night was observed. It is concluded, that the high DI<sub>O</sub>/RC values in October and November at sub-zero temperatures are due to sustained NPQ, associated with Z-mediated constitutive quenching in antenna complexes. In addition damaged oxygen evolving complexes (OEC) also contribute to PSII photoinhibition. During periods of low temperatures, there is an increase in PSII heterogeneity. The photoinhibited PSII may consist of populations devoid of OEC or RCs.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Long-Term Acclimation of PSII in Arctostaphylos uva-ursi Leaves to the Cold Climate of Central Yakutia

  • 期刊论文

  • 发表日期：

    2025年7月5日

查看全文
  • V. E. Sofronova,
  • F. F. Protopopov

摘要

Abstract

The evergreen shrub Arctostaphylos uva-ursi (L.) Spreng. is one of the most common species in the natural flora of Yakutia permafrost ecosystems. The analysis of the OJIP chlorophyll a fluorescence transient curves enabled the determination of adaptive changes in key JIP test parameters during cold hardening of plants under natural conditions. Long-term acclimation of PSII was accompanied by an increase in the relative amounts of QB- and QA-non-reducing centers. In addition, there was a limitation of photosynthetic electron transport activity (ETО/ABS), as well as a steady increase in the values of FK/FJ parameter, which characterizes the extent of inactivation of the PSII donor side. In the range of average daily temperatures from +5°C to –10°C, an increase in the content of zeaxanthin (Z) fraction maintained throughout the day and night was observed. It is concluded, that the high DIO/RC values in October and November at sub-zero temperatures are due to sustained NPQ, associated with Z-mediated constitutive quenching in antenna complexes. In addition damaged oxygen evolving complexes (OEC) also contribute to PSII photoinhibition. During periods of low temperatures, there is an increase in PSII heterogeneity. The photoinhibited PSII may consist of populations devoid of OEC or RCs.