Photosynthetic Parameters Show Specific Responses to Essential Mineral Deficiencies

• Main Authors: Miho Ohnishi (Author), Riu Furutani (Author), Takayuki Sohtome (Author), Takeshi Suzuki (Author), Shinya Wada (Author), Soma Tanaka (Author), Kentaro Ifuku (Author), Daisei Ueno (Author), Chikahiro Miyake (Author)
• Format: Book
• Published: MDPI AG, 2021-06-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antiox10070996; 2076-3921
• Keywords: P700; P700 oxidation system; photosynthesis; photosystem I (PSI); plant nutrition; reactive oxygen species (ROS); Therapeutics. Pharmacology; RM1-950
• Source: Antioxidants, Vol 10, Iss 7, p 996 (2021)

In response to decreases in the assimilation efficiency of CO₂, plants oxidize the reaction center chlorophyll (P700) of photosystem I (PSI) to suppress reactive oxygen species (ROS) production. In hydro-cultured sunflower leaves experiencing essential mineral deficiencies, we analyzed the following parameters that characterize PSI and PSII: (1) the reduction-oxidation states of P700 [Y(I), Y(NA), and Y(ND)]; (2) the relative electron flux in PSII [Y(II)]; (3) the reduction state of the primary electron acceptor in PSII, Q_A (1 − qL); and (4) the non-photochemical quenching of chlorophyll fluorescence (NPQ). Deficiency treatments for the minerals N, P, Mn, Mg, S, and Zn decreased Y(II) with an increase in the oxidized P700 [Y(ND)], while deficiencies for the minerals K, Fe, Ca, B, and Mo decreased Y(II) without an increase in Y(ND). During the induction of photosynthesis, the above parameters showed specific responses to each mineral. That is, we could diagnose the mineral deficiency and identify which mineral affected the photosynthesis parameters.