Redox homeostasis in the growth zone of the rice leaf plays a key role in cold tolerance

Abstract

We analysed the cellular and molecular changes in the leaf growth zone of tolerant and sensitive rice varieties in response to suboptimal temperatures. Cold reduced the final leaf length by 35% and 51% in tolerant and sensitive varieties, respectively. Tolerant lines exhibited a smaller reduction of the leaf elongation rate and greater compensation by an increased duration of leaf growth. Kinematic analysis showed that cold reduced cell production in the meristem and the expansion rate in the elongation zone, but the latter was compensated for by a doubling of the duration of cell expansion. We performed iTRAQ proteome analysis on proliferating and expanding parts of the leaf growth zone. We identified 559 and 542 proteins, of which 163 and 210 were differentially expressed between zones, and 96 and 68 between treatments, in the tolerant and sensitive lines, respectively. The categories protein biosynthesis and redox homeostasis were significantly overrepresented in the up-regulated proteins. We therefore measured redox metabolites and enzyme activities in the leaf growth zone, demonstrating that tolerance of rice lines to suboptimal temperatures correlates with the ability to up-regulate enzymatic antioxidants in the meristem and non-enzymatic antioxidants in the elongation zone.

B2O3 nanoparticles alleviate salt stress in maize leaf growth zones by enhancing photosynthesis and maintaining mineral and redox status

“…Most enzymatic antioxidants showed a higher activity in the division and elongation zones. Consistent with our finding, increased enzymatic antioxidants in rice leaves meristem and nonenzymatic ones in the elongation zone were the reason for its tolerance to suboptimal temperature (Gázquez et al, 2019). Applying BNP under salt stress further increased tocopherol accumulation, and that enforcement appeared at its highest degree in the mature zone, which indicates powerful protection of the photosynthetic apparatus.…”

Rice plants alter their yield component parameters based on their tolerance to low temperatures determined by a non-invasive method during the vegetative stage

“…More recently, additional photosynthesis and growth-related parameters were shown to distinguish between LT sensitive and tolerant rice genotypes, ie. : the net photosynthetic rate (Pn), stomatal conductance (Gs), some OJIP-test parameters and the area below the leaf growth curve (Gazquez et al, 2015; 2018; 2020; Vilas et al, 2020a). The OJIP-test is a technique that depicts in detail the state of structures related to the photosystem II complex (PSII).…”

Determination of low‐temperature stress during the vegetative stage as a tool to predict plant yield in rice genotypes with contrasting tolerance levels

“…Moreover, the photosynthetic performance index has been demonstrated to be a highly sensitive parameter to distinguish between cultivars that differ in yield (Zhang et al, 2015). Recently, additional parameters related to photosynthesis and growth were found to differentiate between LT‐sensitive and LT‐tolerant rice genotypes, such as the net photosynthetic rate, stomatal conductance, certain OJIP‐test parameters and the area under the leaf growth curve (Gazquez et al, 2015, 2018, 2020; Vilas et al, 2020a). The OJIP test is a technique that provides a detailed depiction of the state of structures related to the Photosystem II complex (PSII) through different OJIP parameters.…”