Parkash Ved, Snider John L, Awori Kelvin Jimmy, Pilon Cristiane, Brown Nino, Almeida Ingrid Brito, Tishchenko Viktor
Department of Crop and Soil Sciences, University of Georgia-Tifton Campus, 31793, Tifton, GA, USA.
Department of Crop and Soil Sciences, University of Georgia-Tifton Campus, 31793, Tifton, GA, USA.
Plant Physiol Biochem. 2025 Mar;220:109479. doi: 10.1016/j.plaphy.2025.109479. Epub 2025 Jan 6.
In some peanut (Arachis hypogaea L.) producing regions, growth and photosynthesis-limiting low and high temperature extremes are common. Heat acclimation potential of photosynthesis and respiration is a coping mechanism that is species-dependent and should be further explored for peanut. The objectives of the current study are (1) to evaluate the response of photosynthesis, its component processes, and respiration to low and high temperatures, and (2) to determine the heat acclimation potential of photosynthesis and respiration during early vegetative growth of peanut. Peanut was exposed to four different growth temperature regimes: (1) optimum temperature (30/20 °C day/night), (2) low temperature (20/15 °C), (3) moderately high temperature (35/25 °C), and (4) a high temperature extreme (40/30 °C). Low temperature and both high temperatures caused substantial reductions in growth and net photosynthetic rate. Mesophyll conductance and RuBP regeneration co-limited net photosynthetic rate under low temperature. Rubisco carboxylation was the most negatively impacted biochemical processes by high temperatures; however, diffusional limitations were not evident under high temperature conditions. Photosynthesis did not acclimate to high temperatures, while respiration and photorespiration exhibited heat acclimation. The inability of photosynthesis to acclimate to high temperature is likely a major constraint to early season growth in peanut.
在一些花生（落花生）种植区，生长和光合作用受限的低温和高温极端情况很常见。光合作用和呼吸作用的热适应潜力是一种因物种而异的应对机制，花生的这种机制有待进一步探索。本研究的目的是：（1）评估光合作用及其组成过程以及呼吸作用对低温和高温的响应；（2）确定花生营养生长早期光合作用和呼吸作用的热适应潜力。花生被置于四种不同的生长温度条件下：（1）最适温度（白天30℃/夜间20℃），（2）低温（20℃/15℃），（3）适度高温（35℃/25℃），（4）高温极端条件（40℃/30℃）。低温和两种高温条件均导致生长和净光合速率大幅下降。在低温条件下，叶肉导度和核酮糖-1,5-二磷酸（RuBP）再生共同限制了净光合速率。高温对羧化酶加氧酶（Rubisco）羧化作用的负面影响最大；然而，在高温条件下扩散限制并不明显。光合作用没有适应高温，而呼吸作用和光呼吸表现出热适应。光合作用无法适应高温可能是花生早期生长的一个主要限制因素。
