Red and Blue Light Affect the Formation of Adventitious Roots of Tea Cuttings (Camellia sinensis) by Regulating Hormone Synthesis and Signal Transduction Pathways of Mature Leaves

Abstract

Light is an important environmental factor which affects plant growth, through changes of intensity and quality. In this study, monochromatic white (control), red (660 nm), and blue (430 nm) light-emitting diodes (LEDs) were used to treat tea short cuttings. The results showed the most adventitious roots in blue light treated tea cuttings, but the lowest roots in that treated by red light. In order to explore the molecular mechanism of light quality affecting adventitious root formation, we performed full-length transcriptome and metabolome analyses of mature leaves under three light qualities, and then conducted weighted gene co-expression network analysis (WGCNA). Phytohormone analysis showed that Indole-3-carboxylic acid (ICA), Abscisic acid (ABA), ABA-glucosyl ester (ABA-GE), trans-Zeatin (tZ), and Jasmonic acid (JA) contents in mature leaves under blue light were significantly higher than those under white and red light. A crosstalk regulatory network comprising 23 co-expression modules was successfully constructed. Among them, the “MEblue” module which had a highly positive correlation with ICA (R = 0.92, P = 4e-04). KEGG analysis showed that related genes were significantly enriched in the “Plant hormone signal transduction (ko04075)” pathway. YUC (a flavin-containing monooxygenase), AUX1, AUX/IAA, and ARF were identified as hub genes, and gene expression analysis showed that the expression levels of these hub genes under blue light were higher than those under white and red light. In addition, we also identified 6 auxin transport-related genes, including PIN1, PIN3, PIN4, PILS5, PILS6, and PILS7. Except PILS5, all of these genes showed the highest expression level under blue light. In conclusion, this study elucidated the molecular mechanism of light quality regulating adventitious root formation of tea short cutting through WGCNA analysis, which provided an innovation for “rapid seedling” of tea plants.

Response of photomorphogenesis and photosynthetic properties of sweet pepper seedlings exposed to mixed red and blue light

“…Difference in lower-case letters indicates significant difference at P < 0.05. Shen et al, 2022), and thus longer root under 3R1B in this study might be related to higher IAA accumulation in root. Therefore, the better root development of pepper seedlings exposed to 3R1B leads to faster acclimatization.…”

“…(2015) , this growth may be related to the ability of 3R1B treatment to induce the formation of endogenous GA, which is an important growth regulator involved in cell elongation. Furthermore, the increase in root length and formation of adventitious roots for pepper seedlings under 3R1B may be due to IAA levels, as this treatment promoted polar IAA transport from apical shoot to downward portion, which regulated by genes involved in auxin formation and signal transduction as well as auxin transportation ( Liu et al., 2011 ; Shen et al., 2022 ), and thus longer root under 3R1B in this study might be related to higher IAA accumulation in root. Therefore, the better root development of pepper seedlings exposed to 3R1B leads to faster acclimatization.…”

Comprehensive applications of metabolomics on tea science and technology: Opportunities, hurdles, and perspectives

“…In contrast, red light (600–699 nm) can enhance photosynthesis, thus elevating the accumulation of carbohydrates (Yue et al., 2021). Additionally, red and blue lights encourage the lengthening and thickening of tea roots, respectively, while blue light can promote the formation of more adventitious roots by producing more phytohormones (Shen et al., 2022).…”

Transcriptome analysis reveals that auxin promotes strigolactone-induced adventitious root growth in the hypocotyl of melon seedlings

“…For example, indole-3-carboxylic acid, ABA, trans-zeatin, and JA levels change during AR formation in tea. Moreover, a transcriptome analysis of ARs under different light treatments showed that differentially expressed genes (DEGs) were significantly enriched in the plant hormone synthesis and transduction-related pathway, including flavin monooxygenase ( YUC ) and auxin influx carrier ( AUX1 ) ( Shen et al., 2022 ). In apple rootstock, the levels of the endogenous phytohormones indole-3-acetic acid (IAA), zeatin riboside, JA, GA, and ABA in the process of AR formation were changed, and DEGs were shown to be considerably enriched in hormone signaling-related pathways ( Tahir et al., 2021 ).…”