Physiological analysis of the effect of altitudinal gradients on Leymus secalinus on the Qinghai-Tibetan Plateau

Abstract

On the Qinghai-Tibetan Plateau, the high-altitudinal gradients can negatively affect plant distribution and limit plant growth and reproduction. Leymus secalinus (Georgi) Tzvel. is an important forage crop on the Qinghai-Tibetan Plateau and has an excellent ability to fix sand and improve soil. To evaluate the effect of altitude on the physiological characteristics of L. secalinus on the Qinghai-Tibetan Plateau, we measured the lipid peroxidation; chlorophyll a (Chl a), chlorophyll b (Chl b), total carotenoid (Car), soluble protein, proline and soluble sugar contents; and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in leaves from eight different altitudes in Minhe County and Huangzhong County. The leaves were collected at the initial bloom stage, and the average vertical distance between two adjacent collection sites was approximately 100 meters. The reduction in Chl a and Chl b contents and the increase in Car contents can allow plants to weaken their light absorption and avoid photodamage to the chloroplast. The decrease in malondialdehyde (MDA) content associated with lower lipid peroxidation, and the changes of CAT, SOD and POD activities reflect a higher reactive oxygen species (ROS) scavenging capacity in high-altitude plants. The increase in proline and soluble sugar contents with elevation suggests that proline and soluble sugar may play a key role in the osmotic adjustment of plants in alpine regions. The results suggested that altitudinal gradients negatively affect L. secalinus on the Qinghai-Tibetan Plateau and that the adaptation mechanism and survival strategies of L. secalinus were attributed to the combined effects of multiple protective strategies.

Changes in Metabolome and Nutritional Quality of Lycium barbarum Fruits from Three Typical Growing Areas of China as Revealed by Widely Targeted Metabolomics

“…Negative influence of altitude gradient was also shown on the growth and synthesis of some metabolites (photosynthetic pigments, malondialdehyde, etc.) in Leymus secalinus, assessed across eight different altitudes in the Qinghai-Tibetan Plateau [41]. However, these authors observed that proline, soluble sugar contents and other markers of stress increased with elevation.…”

Investigating the Relationship of Genotype and Geographical Location on Volatile Composition and Sensory Profile of Celery (Apium graveolens)

“…Possibly the most obvious difference between geographical location would be the altitude of each field: UK celery was grown on an east-facing field that was −1 to 1 m above sea level, whereas the field in Aguilas was south-facing at 390 m above sea level. Higher altitudes will result in lower temperatures and limitations on light exposure [ 61 ]. Cui et al [ 61 ] investigated the physiological changes of Leymus secalinus and the effect of altitude, observing an increase in soluble sugars as elevation increased but a decrease in chlorophyll a and b , leading to a decrease in the crop’s ability to absorb light.…”

“…Higher altitudes will result in lower temperatures and limitations on light exposure [ 61 ]. Cui et al [ 61 ] investigated the physiological changes of Leymus secalinus and the effect of altitude, observing an increase in soluble sugars as elevation increased but a decrease in chlorophyll a and b , leading to a decrease in the crop’s ability to absorb light. Both these reactions were noted as defence mechanisms and adaption strategies to the change in environment.…”

Effect of UV Radiation and Other Abiotic Stress Factors on DNA of Different Wild Plant Species Grown in Three Successive Seasons in Alpine and Subalpine Regions

“…The adaptation strategies to the elevation can be triggered in the plants as a result of combined effects of multiple environmental factors such as increase in UV radiation, increase in the atmospheric pressure, decrease in the temperatures, alteration in precipitation, alteration in CO 2 and O 2 concentrations with elevation [54]. Herbs that have a cushion-like habit, such as representative of the Saxifragaceae family, can also be significant to local species richness.…”

“…Plants have developed various adaptation strategies to overcome the environmental stress and to survive in extreme environmental conditions at high altitudes, such as synthesis of photoprotective compounds [16], activation of the plants' antioxidant defense system, stress related hormones, osmotic adjustment, morphological alterations in some structures, etc. [17,19,48,[51][52][53][54].…”