Rapid metabolite response in leaf blade and petiole as a marker for shade avoidance syndrome.

Abstract

Background Shade avoidance syndrome (SAS) commonly occurs in plants experiencing vegetative shade, causing morphological and physiological changes that are detrimental to plant health and consequently crop yield. As the effects of SAS on plants are irreversible, early detection of SAS in plants is critical for sustainable agriculture. However, conventional methods to assess SAS are restricted to observing for morphological changes and checking the expression of shade-induced genes after homogenization of plant tissues, which makes it difficult to detect SAS early. Results Using the model plant Arabidopsis thaliana , we introduced the use of Raman spectroscopy to measure shade-induced changes of metabolites in vivo. Raman spectroscopy detected a decrease in carotenoid contents in leaf blades and petioles of plants with SAS, which were induced by low Red:Far-red light ratio or high density conditions. Moreover, by measuring the carotenoid Raman peaks, we were able to show that the reduction in carotenoid content under shade was mediated by phytochrome signaling. Carotenoid Raman peaks showed more remarkable response to SAS in petioles than leaf blades of plants, which greatly corresponded to their morphological response under shade or high plant density. Most importantly, carotenoid content decreased shortly after shade induction but before the occurrence of visible morphological changes. We demonstrated this finding to be similar in other plant species. Comprehensive testing of Brassica vegetables showed that carotenoid content decreased during SAS, in both shade and high density conditions. Likewise, carotenoid content responded quickly to shade, in a manner similar to Arabidopsis plants. Conclusions In various plant species tested in this study, quantification of carotenoid Raman peaks correlate to the severity of SAS. Moreover, short-term exposure to shade can induce the carotenoid Raman peaks to decrease. These findings highlight the carotenoid Raman peaks as a biomarker for early diagnosis of SAS in plants.

Plant phenotyping relevance

Raman分光法で植物体内のカロテノイド変化を非破壊測定し、形態変化前の遮蔽回避症候群を定量・早期診断する方法を開発・検証しており、植物表現型取得が中心である。

Code and data availability

The paper reports Raman spectroscopy measurements of carotenoid peaks in shade-treated plants, but no public dataset, image, code, or model deposit is described. The availability statement says all data are within the article and its Additional files 1 and 2, with no authors' public URL or repository identifier. The ar

No evidence-backed public reproduction asset is currently recorded.