Physiological and Gene Expression Changes of Clematis crassifolia and Clematis cadmia in Response to Heat Stress

Abstract

Clematis is a superior perennial ornamental vine known for varied colors and shapes of its flowers. Clematis crassifolia is sensitive to high temperature, whereas Clematis cadmia has a certain temperature adaptability. Here we analyzed the potential regulatory mechanisms of C. crassifolia and C. cadmia in response to heat stress by studying the photosynthesis, antioxidant parameters, amino acids, and gene expression patterns under three temperature treatments. Heat stress caused the fading of leaves; decreased net photosynthetic rate, stomatal conductance, superoxide dismutase, and catalase activity; increased 13 kinds of amino acids content; and up-regulated the expression of seven genes, including C194329_G3, C194434_G1, and C188817_g1, etc., in C. crassifolia plants. Under the treatments of heat stress, the leaf tips of C. cadmia were wilted, and the net photosynthetic rate and soluble protein content decreased, with the increase of 12 amino acids content and the expression of c194329_g3, c194434_g1, and c195983_g1. Our results showed that C. crassifolia and C. cadmia had different physiological and molecular response mechanisms to heat stress during the ecological adaptation.

Comparative transcriptome analysis of heat stress responses of Clematis lanuginosa and Clematis crassifolia

“…This indicates that the accumulation of amino acids and the activation of thiamine metabolic pathways may be important in the response of C. lanuginosa to heat stress. A previous study confirmed that heat stress can promote the accumulation of arginine and proline content in C. crassifolia [ 61 ]. The differentially expressed genes in C. crassifolia were specifically upregulated in phenylalanine metabolism, arginine/proline metabolism and the flavonoid biosynthesis classificantions.…”

Nitrogen Allocation Tradeoffs Within-Leaf between Photosynthesis and High-Temperature Adaptation among Different Varieties of Pecan (Carya illinoinensis [Wangenh.] K. Koch)

“…Growth–defense tradeoffs commonly occur in plants triggered by environmental restrictions, and their function in optimizing growth and defense depends jointly on internal and external factors [ 13 ]. In this study, pecans allocated 25.72–39.76% of leaf N to the photosynthetic apparatus ( P p , Figure 3 ), which was lower than the result in C3 plants (≥50%) [ 14 , 34 ]. The difference may result from chlorophyll degradation at high temperatures [ 34 ] and accompanying higher solar radiation intensity [ 35 ], because leaf N invested in photosynthesis could be affected by species and environment, ranging from 30–70% [ 36 ].…”

“…In this study, pecans allocated 25.72–39.76% of leaf N to the photosynthetic apparatus ( P p , Figure 3 ), which was lower than the result in C3 plants (≥50%) [ 14 , 34 ]. The difference may result from chlorophyll degradation at high temperatures [ 34 ] and accompanying higher solar radiation intensity [ 35 ], because leaf N invested in photosynthesis could be affected by species and environment, ranging from 30–70% [ 36 ]. For photosynthetic capacity, rubisco is the key enzyme in charge for carboxylation [ 16 , 37 ], contributing to P r and accounting for a major portion of P p in the eight varieties of pecan ( Figure 3 ).…”

Comparison of the Differences in Tolerance to Drought Stress across Five Clematis Species Based on Seed Germination and Seedling Growth

“…in China has predominantly centered on their medicinal properties [18]. Investigation into their ornamental characteristics is limited to species like Clematis vitalba [19], Clematis crassifolia, and Clematis cadmia [20], found in the southern regions of China. There remains a significant gap in the research on wild Clematis spp., particularly those species growing in arid and semi-arid environments, within the realms of urban landscaping and drought resilience.…”