Evidence of brassinosteroid signalling and alternate carbon metabolism pathway in the particulate matter and volatile organic compound stress response of Sansevieria trifasciata

Phytoremediation has become a popular technology due to its low cost, sustainability, and environmentally friendly use for removing particulate matter (PM) and volatile organic compound (VOC) pollution. However, pollution is detrimental to plant growth under stressful conditions and can even cause plant death. Physiology and proteomics approaches were used to explain a comprehensive stress response mechanism to provide better knowledge of plants’ response to PM and VOC stress. In this study, Sansevieria trifasciata, a typical air phytor- emediation plant, was exposed to PM and VOC stress conditions generated from cigarette smoke in a 15 L chamber for six cycles, with the fifth cycle being a recovery period (30 days without smoke). Plant physiological stress responses were examined, such as chlorophyll, carotenoid, and malondialdehyde (MDA) content. Exposure to PM and VOCs increased plant MDA content by cycles three and four but not chlorophyll and carotenoid. The exposure continuously caused plant stress, while the recovery period of 30 days relieved the stress. The prote- omics results showed that plants might activate brassinosteroid signalling under PM and VOCs, which initiated the photosynthesis and antioxidant system. The plant might use an alternate carbon metabolism pathway through the folate cycle to provide carbon sources for synthesising other metabolites. This study is the first proteomics approach to show the response of proteins under PM and VOC stress in S. trifasciata. Understanding the plant stress response may enable a guideline to provide well-being conditions for phytoremediation.