Ecophysiological Traits of Invasive C3 Species Calotropis procera to Maintain High Photosynthetic Performance Under High VPD and Low Soil Water Balance in Semi-Arid and Seacoast Zones

Abstract

The evergreen C 3 plant Calotropis procera is native to arid environments. Thus, it grows under high vapor pressure deficit (VPD), intense light, and severe drought conditions. We measured several ecophysiological traits in C. procera plants growing in semi-arid and seacoast environments to assess the attributes that support its photosynthetic performance under these contrasting conditions. Gas exchange analysis, primary metabolism content, nutrients, the antioxidant system, and leaf anatomy traits were measured under field conditions. In the semi-arid environment, C. procera was exposed to a prolonged drought season with a negative soil water balance during the 2 years of the study. Calotropis procera plants were exposed to a positive soil water balance only in the rainy season in the seacoast environment. The leaves of C. procera showed the same photosynthetic rate under high or low VPD, even in dry seasons with a negative soil water balance. Photosynthetic pigments, leaf sugar content, and the activity of antioxidant enzymes were increased in both places in the dry season. However, the anatomical adjustments were contrasting: while, in the semi-arid environment, mesophyll thickness increased in the driest year, in the seacoast environment, the cuticle thickness and trichome density were increased. The ability to maintain photosynthetic performance through the seasons would be supported by new leaves with different morpho-anatomical traits, with contrasting changes between semi-arid and seacoast environments. Furthermore, our results suggest that an efficient antioxidative system and leaf sugar dynamics can contribute to protecting the photosynthetic machinery even under severe drought.

Foliar Functional Traits of Resource Island-Forming Nurse Tree Species from a Semi-Arid Ecosystem of La Guajira, Colombia

“…In the characterization of the foliar biochemical traits, it was observed that H. brasiletto, and P. dulce presented higher contents of Chl a , Chl b , Chl total , and C than P. guamacho, which may be a possible cause of the better performance in quantum efficiency in these two species since chlorophyll is key to light harvesting and biochemical energy production in the photosynthetic process [29,68,69], and carotenoids play a special role in protecting PSII from photooxidative damage, allowing the dissipation of PSII energy as heat [28,29,70]. For photosynthetic pigments, a positive correlation has been observed between chlorophyll content and chlorophyll a fluorescence parameters [71].…”

An Overview of the Characteristics and Potential of Calotropis procera From Botanical, Ecological, and Economic Perspectives

“…Calotropis procera has an exceptional ability to adapt and maintain productivity in severe arid conditions (Ramadan et al, 2014). It is a C 3 plant that can survive drought, salinity, extreme temperatures, high vapor pressure deficit, and high photosynthetic active radiations (Frosi et al, 2013;Rivas et al, 2020). It can easily thrive in prolonged dry seasons with rainfall >150 mm per year (Dhileepan, 2014).…”

“…The plant also shows physiological and biochemical adaptations in terms of gas exchange and metabolic adjustments (Frosi et al, 2013). An efficient antioxidative system, leaf sugar dynamics, and photoprotective mechanisms guard the photosynthetic machinery of the plant under an extreme xerophytic environment (Rivas et al, 2017(Rivas et al, , 2020. Furthermore, the plant maintains a high photosynthetic rate despite reduced stomatal conductance, thus increasing water use efficiency, which is a fundamental characteristic for survival in arid and semi-arid ecosystems (Tezara et al, 2011;Frosi et al, 2013) as well as being able to quickly adjust the aquaporins of the root system when under salt stress (Coêlho et al, 2021).…”

“…In South America, the plant was introduced for ornamental and forage purposes; however, it has spread beyond the introduced areas by colonizing habitats with different environmental characteristics (Rivas et al, 2020). It is said to be an aggressive invader of the Caatinga ecoregion (Al Sulaibi et al, 2020) and others regions of northeastern Brazil where it has been introduced at the beginning of the nineteenth century (Frosi et al, 2013).…”

EFFECTS OF ARTIFICIAL SHADING AND IRRIGATION WITH BRACKISH WATER ON THE INITIAL DEVELOPMENT OF Anadenanthera colubrina (Vell.) Brenan PLANTS

“…In this region, the burning of wood from native vegetation for energy production has become one of the main sources of income and a devastating form of environmental degradation (Araújo Filho, 2013;Santos et al, 2014). However, this biome has a delicate balance and suff ers with the intemperate climate, which favors degradation, since the abiotic factors (drought, radiation, high temperatures and salinity of the water) exert great infl uence on the vegetation (Silva et al, 2017;Lima et al, 2018a;Rivas et al, 2020).…”