Physiology Response and Resistance Evaluation of Twenty Coconut Germplasm Resources under Low Temperature Stress

Abstract

Coconut (Cocos nucifera L.) is a tropical evergreen crop with high economic value. Low temperature is one of the main environmental factors that limit coconut productivity. Therefore, it is necessary and significant to research the growth trend and physiological changes of coconuts under a low temperature environment. In this study, the physiological response of 20 coconut germplasm resources is presented in an integrated perspective to provide a holistic view of the behavior of coconut trees facing cold stress under four temperature conditions (25 °C, 15 °C, 10 °C, 5 °C). It was shown that low temperature would lead to the increase of relative electrical conductivity, MDA content, soluble protein content, and proline content. In addition, the activities of defense enzymes (SOD, POD, CAT, APX) were increased to resist the cold environment. In a comprehensive analysis, it was revealed that coconut germplasms with high cold resistance, such as C2, C7, and C10 as well as POD activity, proline content, and soluble protein content, were defined as representatives for coconut cold resistance evaluation. Through the exploration of osmotic adjustment substances and defense enzymes, the breeding and quality improvement of cold-resistant coconut varieties could be promoted. As a result, understanding the physiological response and tolerance mechanisms of coconuts to low temperature stress was essential, as this perception may serve as the foundation for coconut resistance evaluation, cultivation, and breeding.

Comparative physiological analyses and the genetic basis reveal heat stress responses mechanism among different Betula luminifera populations

“…Therefore, for the response of B. luminifera under heat treatment, the RS population was the Frontiers in Plant Science 12 frontiersin.org representative of the six populations. In addition, physiological responses of different geographical populations to stress treatments that were significantly different have also been reported for other woody plants such as Cocos nucifera (Sun et al, 2021), Azadirachta indica (Zheng et al, 2008), and Quercus variabilis (Zhang et al, 2017). Therefore, analyzing the tolerance of B. luminifera seedlings from different populations under heat stress is of great help to select provenances with excellent resistance and to find artificial measures to improve the survival of seedlings.…”

“…Proline (Pro) is a typical osmotic adjustment substance, which is commonly used to estimate plant resistance to diverse abiotic stimuli (Zhang et al, 2017;Ren et al, 2019;Sun et al, 2021). Pro helps to adjust and maintain the cell osmotic balance, participates in decreasing cell redox potential reactions and is an important indicator of the heat response in plants.…”

“…Additionally, it has been found that heat stress can alter the integrity of thylakoid membranes and the ultrastructure of chloroplasts (Allakhverdiev et al, 2008;Yamamoto et al, 2008), which greatly reduced plant thermotolerance. Based on the determination of physiological parameters under stress treatment, the response mechanisms of transcriptomics and metabolomics were analyzed for Populus tomentosa under heat stress (Ren et al, 2019); 20 coconut populations' physiology response and resistance evaluation were obtained under low-temperature stress (Sun et al, 2021); and the physiological and transcriptomic response mechanism of Santalum album were revealed (Zhang et al, 2017). Therefore, the determination of physiological indexes is an effective means to assess plant responses to heat stress.…”

Outcomes of Low-Temperature Stress on Biological Alterations within Pothos (Epipremnum aureum) Leaves

“…This suggested that E. aureum can, to a certain extent, clear LTS-induced ROS by promoting the antioxidant enzymatic activity in order to reduce the cell membrane damage, and better adapt to the external environment. However, in coconuts (Cocos nucifera) [44], the POD and CAT activities demonstrated a gradual rising trend with decreasing temperature.…”

Physio-Biochemical Insights into the Cold Resistance Variations among Nectarine (Prunus persica (L.) Batsch var. nectarina) Cultivars

“…For the determinations of osmoregulatory substance contents, antioxidant enzymes activities and phytohormones contents, the middle part to shoots (excluding flower and leaf buds) from each nectarine cultivar were used. Shoots were cut into small sections, ground into homogenate in 10% trichloroacetic acid solution and subjected to malondialdehyde (MDA) content determination using the Thiobarbituric acid method [29]. For the determination of proline (PRO) content, 0.5 g shoot sections were added into 5 mL 3% sulfosalicylic acid solution, kept in boiling water for 10 min for PRO extraction, and detected using acid ninhydrin method [30].…”