Phosphoproteomic Analysis of Thermomorphogenic Responses in Arabidopsis

Abstract

Plants rapidly adapt to elevated ambient temperature by adjusting their growth and developmental programs. To date, a number of experiments have been carried out to understand how plants sense and respond to warm temperatures. However, how warm temperature signals are relayed from thermosensors to transcriptional regulators is largely unknown. To identify new early regulators of plant thermo-responsiveness, we performed phosphoproteomic analysis using TMT (Tandem Mass Tags) labeling and phosphopeptide enrichment with Arabidopsis etiolated seedlings treated with or without 3h of warm temperatures (29°C). In total, we identified 13,160 phosphopeptides in 5,125 proteins with 10,700 quantifiable phosphorylation sites. Among them, 200 sites (180 proteins) were upregulated, while 120 sites (87 proteins) were downregulated by elevated temperature. GO (Gene Ontology) analysis indicated that phosphorelay-related molecular function was enriched among the differentially phosphorylated proteins. We selected ATL6 (ARABIDOPSIS TOXICOS EN LEVADURA 6) from them and expressed its native and phosphorylation-site mutated (S343A S357A) forms in Arabidopsis and found that the mutated form of ATL6 was less stable than that of the native form both in vivo and in cell-free degradation assays. Taken together, our data revealed extensive protein phosphorylation during thermo-responsiveness, providing new candidate proteins/genes for studying plant thermomorphogenesis in the future.

CCaP1/CCaP2/CCaP3 interact with plasma membrane H+-ATPases and promote thermo-responsive growth by regulating cell wall modification in Arabidopsis

“…In Arabidopsis , the growth of the hypocotyl (the embryonic stem) is influenced by transcription factors PIF4 and PIF7, which promote cell division through the auxin-responsive pathway ( Casal and Balasubramanian, 2019 ). However, recent research has shown that, even in the absence of PIF4 and PIF7, the hypocotyl still elongates at warm temperatures in the dark ( Shao et al., 2021 ), suggesting the existence of additional pathways that regulate plant growth in response to temperature. One such pathway, independent of PIF4 and phytochrome B, involves a signaling molecule known as TARGET OF TEMPERATURE 3 (TOT3), along with two related molecules from the mitogen-activated protein kinase kinase kinase kinase (MAP4K) family ( Vu et al., 2021 ).…”

Transcription factors NF-YB involved in embryogenesis and hormones responses in Dimocarpus Longan Lour

“…In A. thaliana, AtNF-YB3 forms NF-Y complex with AtNF-YA2 and AtNF-YC10 (Sato et al, 2014), which was involved in plant heat stress response and improved plant survival rate, and overexpression of AtNF-YB3 plants enhanced heat resistance (Sato et al, 2019). AtNF-YB10 inhibited hypocotyl elongation induced by mild and heat stresses under light, suggesting that AtNF-YB10 may be a negative regulator of thermomorphogenesis (Shao, 2022). Analysis of the cis-acting elements of the promoter revealed that the DlNF-YB family contained many CCAAT boxes.…”

“…At present, NF-YB gene family has been cloned and identified in many plants, including 13 in Oryza sativa L. (Zhou et al, 2018), 21 in Zea mays (Xu et al, 2019), and 28 in Glycine max (Zheng et al, 2012). The NF-YB11 in Triticum aestivum responded to drought stress by regulating downstream gene expression (Zhao et al, 2022), overexpression of NF-YB10 inhibited hypocotyl elongation and upregulated the expression of heat response genes under high temperature stress of Arabidopsis thaliana (Shao, 2022). The PbNF-YB21 promoted root growth with highly lignified and enlarged xylem vessels and enhanced drought resistance by abscisic acid-mediated indoleacetic acid transport (Zhou et al, 2020).…”