Photosynthetic capacity of senescent leaves for a subtropical broadleaf deciduous tree species Liquidambar formosana Hance

Abstract

Photosynthetic capacity and leaf life span generally determine how much carbon a plant assimilates during the growing season. Leaves of deciduous tree species start senescence in late season, but whether the senescent leaves still retain capacity of carbon assimilation remains a question. In this study, we investigated leaf phenology and photosynthesis of a subtropical broadleaf deciduous tree species Liquidambar formosana Hance in the central southern continental China. The results show that L. formosana has extended leaf senescence (more than 2 months) with a substantial number of red leaves persisting on the tree. Leaf photosynthetic capacity decreases over season, but the senescent red leaves still maintain relatively high photosynthetic capacity at 42%, 66% and 66% of the mature leaves for net photosynthesis rate, apparent quantum yield, and quantum yield at the light compensation point, respectively. These results indicate that L. formosana may still contribute to carbon sink during leaf senescence.

Paclobutrazol Application Favors Yield Improvement of Maize Under Semiarid Regions by Delaying Leaf Senescence and Regulating Photosynthetic Capacity and Antioxidant System During Grain-Filling Stage

“…The down-regulation of photosynthetic capacity during the senescence has been widely documented in the previous studies [5,7,12,16]. In our present study, the net photosynthetic rate of maize plants declined gradually with the increase in days after silking in all treatments.…”

“…Under semiarid water deficit regions, the senescence often starts before the complete development of all leaf area and progresses at an increased rate during the grain filling period [5]. Leaf senescence causes the disintegration of chlorophyll pigments, inhibition of photosynthesis-related protein and enzymes, thereby reducing the overall photosynthetic capacity [11,12]. In maize, the grain-filling process is greatly dependent on the active photosynthetic area, and the photo-assimilates formed after silking contributes to more than 80% of the grain yields [8,13].…”

De novo Characterization of the Platycladus orientalis Transcriptome and Analysis of Photosynthesis-Related Genes during Aging

“…The accumulation of reactive oxygen species (ROS) is regulated by peroxidase (POD), superoxide dismutase (SOD), and carotenoids during leaf senescence [18]. However, more research of the relative contributions of the chlorophyll and carotenoid contents to oxidative stress associated with aging in woody perennials is needed [19].Photosynthesis converts light energy into chemical energy, and the electron transfer that occurs during the energy conversion process is regulated by the reduction-oxidation (redox) system [19]. The chlorophyll content decreases during senescence, leading to decreases in the amounts of ATP and NADPH consumed by the photosynthetic carbon cycle [20].…”

“…The accumulation of reactive oxygen species (ROS) is regulated by peroxidase (POD), superoxide dismutase (SOD), and carotenoids during leaf senescence [18]. However, more research of the relative contributions of the chlorophyll and carotenoid contents to oxidative stress associated with aging in woody perennials is needed [19].…”

“…Photosynthesis converts light energy into chemical energy, and the electron transfer that occurs during the energy conversion process is regulated by the reduction-oxidation (redox) system [19]. The chlorophyll content decreases during senescence, leading to decreases in the amounts of ATP and NADPH consumed by the photosynthetic carbon cycle [20].…”