Leaf color change and photosystem function evaluation under heat treatment revealed the stress resistance variation between Loropetalum chinense and L. chinense var. rubrum

Wenqi Cai; Damao Zhang; Xia Zhang; Qianru Chen; Yang Liu; Ling Lin; Lili Xiang; Yujie Yang; Lu Xu; Xiaoying Yu; Yanlin Li

doi:10.7717/peerj.14834

Leaf color change and photosystem function evaluation under heat treatment revealed the stress resistance variation between Loropetalum chinense and L. chinense var. rubrum

PeerJ. 2023 Feb 13:11:e14834. doi: 10.7717/peerj.14834. eCollection 2023.

Authors

Wenqi Cai^#^{1

2

3}, Damao Zhang^#^{1

2

3}, Xia Zhang^{1

2

3}, Qianru Chen^{1

2

3}, Yang Liu^{1

2

3}, Ling Lin⁴, Lili Xiang^{1

2

3}, Yujie Yang^{1

2

3}, Lu Xu^{1

2

3}, Xiaoying Yu^{1

2

3}, Yanlin Li^{1

2

3

5}

Affiliations

¹ College of Horticulture, Hunan Agricultural University, Changsha, Hunan Province, China.
² Ministry of Education, Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Changsha, Hunan Province, Chian.
³ Hunan Mid-Subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, Hunan Province, Chian.
⁴ School of Economics, Hunan Agricultural University School of Economics, Changsha, Hunan Province, China.
⁵ Kunpeng Institute of Modern Agriculture China, Foshan, Guangdong Province, China.

^# Contributed equally.

Abstract

This research mainly focused on the leaf color change and photosystem function differentiation between Loropetalum chinense and its variety L. chinense var. rubrum under heat stress, which were tightly concerned about their ornamental traits and growth. L. chinense 'Xiangnong Xiangyun' (X) and L. chinense var. rubrum 'Xiangnong Fendai' (F) and L. chinense var. rubrum 'Hei Zhenzhu' (H) were chosen to be experimented on to investigate whether leaf color morphology and pigment composition could influence the adaptability of plants to high temperature in order to select foliage plants which posses stable leaf color and better adaptability for hot regions. The plants were cultured in hot environment (40 °C/33 °C, day/night) and normal environment (25 °C/18 °C, day/night). Phenotype and anatomic observation of three cultivars were made and leaf color indices and pigment contents were measured. During the experiment, H and F gradually turned green, total anthocyanins contents significantly decreased in them, however, chlorophyll b contents increased in all three cultivars. In addition, the initial fluorescence (F_o) decreased in X, while increased in H and F. For the maximum fluorescence (F_m) and maximum photochemical efficiency of PSII (F_v/F_m), they only increased in H and decreased in both F and X. The non-photochemical chlorophyll fluorescence quenching (NPQ) also increased in H and decreased in F. For X, it increased at first then gradually decreased. The coefficient of photochemical quenching all increased at first then gradually decreased. Correlation analysis between showed that there was relatively strong connection between anthocyanins, flavonoids and chlorophyll fluorescence parameters, especially NPQ, proved anthocyanins and flavonoids might not only involved in enriching leaf color, but also interfered with the protection of photosystem. Generally speaking, we found higher anthocyanin and flavonoids content level not only dramatically enriched the leaf color of L. chinense var. rubrum cultivars, but also offered more potential antioxidant to keep their normal growth when encountered heat stress.

Keywords: Heat stress; Leaf color; Loropetalum chinense var. rubrum; Photosystem function.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anthocyanins* / analysis
Chlorophyll / analysis
Heat-Shock Response
Photosynthesis*
Plant Leaves / chemistry

Substances

Anthocyanins
Chlorophyll

Grants and funding

The work is funded by the Innovation training program for Open Project of Horticulture Discipline of Hunan Agricultural University (2021YYXK001), the Forestry Science and Technology Innovation Foundation of Hunan Province for Distinguished Young Scholarship (XLKJ202205), the Found of Changsha Municipal Science and Technology Bureau, KQ2202227, the Hunan Provincial Natural Science Youth Foundation Project (2020JJ5264), the Hunan Provincial Education Department Teaching reform Project (2021JGYB101), and the Hunan Agricultural University Teaching reform research project (XJJG-2020-071). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.