The effect of exogenous melatonin on waterlogging stress in Clematis

• Published in: Frontiers in plant science Vol. 15; p. 1385165
• Main Authors: Chen, Kai, Hu, Qingdi, Ma, Xiaohua, Zhang, Xule, Qian, Renjuan, Zheng, Jian
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 18-06-2024
• Subjects: Clematis lanuginosa; Clematis tientaiensis; physiological analysis; Plant Science; transcription factor; transcriptome analysis; waterlogging; transcription factor; transcriptome analysis; Clematis tientaiensis; Clematis lanuginosa; physiological analysis; waterlogging
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2024.1385165

is the queen of the vines, being an ornamental plant with high economic value. Waterlogging stress reduces the ornamental value of the plant and limits its application. Melatonin plays an important role in plant resistance to abiotic stresses. In this study, the physiological responses and gene expression levels of two wild species, namely,
and
, and two horticultural varieties, namely, 'Sen-No-Kaze' and 'Viva Polonia,' under waterlogging stress were analyzed to determine the effect of melatonin on waterlogging tolerance. The results showed that the waterlogging tolerances of
and 'Sen-No-Kaze' were relatively poor, but were significantly improved by concentrations of 100 μmol·L
and 50 μmol·L
melatonin.
and 'Viva Polonia' had relatively strong tolerance to waterlogging, and this was significantly improved by 200 μmol·L
melatonin. Under waterlogging stress, the relative conductivity and H
O
content of
increased significantly; the photosynthetic parameters and chlorophyll contents were significantly decreased; photosynthesis was inhibited; the contents of soluble protein and soluble sugars were decreased. Effective improvement of waterlogging tolerance after exogenous melatonin spraying, the relative conductivity was decreased by 4.05%-27.44%; the H
O
content was decreased by 3.84%-23.28%; the chlorophyll content was increased by 35.59%-103.36%; the photosynthetic efficiency was increased by 25.42%-45.86%; the antioxidant enzyme activities of APX, POD, SOD, and CAT were increased by 28.03%-158.61%; the contents of proline, soluble protein, and soluble sugars were enhanced, and cell homeostasis was improved. Transcription sequencing was performed on wild
with differences in waterlogging tolerance, and nine transcription factors were selected that were highly correlated with melatonin and that had the potential to improve waterlogging tolerance, among which
, and
were significantly positively correlated with the antioxidant enzyme system, and
,
, and
were significantly negatively correlated. Photosynthetic capacity was positively correlated with
and
while being significantly negatively correlated with
,
,
,
and
. Melatonin could enhance the flooding tolerance of
by improving photosynthetic efficiency and antioxidant enzyme activity. This study provides an important basis and reference for the application of melatonin in waterlogging-resistant breeding of
.