Mechanisms of Low-temperature Tolerance in Cucumber Leaves of Various Ages

Abstract

<jats:p>To determine whether differential tolerance to paraquat among cucumber (<jats:italic>Cucumis sativus</jats:italic> L.) leaves of various ages correlates with low-temperature tolerance, leaves of three cultivars at the four-leaf stage were exposed to 5 °C. Leaves tolerant to paraquat were also tolerant to low temperature as indicated by electrolyte leakage changes in leaf tissue, lipid peroxidation, and photosynthesis measurements. The youngest leaf (leaves were numbered 1 to 4 with the youngest leaf given 4) on the same plant was more tolerant than older leaves to low temperature. During chilling, lipid peroxidation and H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> content increased in the oldest leaf when compared with the three younger leaves. Photosynthetic activity and chlorophyll a fluorescence (F<jats:sub>v</jats:sub>/F<jats:sub>m</jats:sub>) were significantly lower in leaf 1 than in leaf 4. There was no difference in superoxide dismutase, catalase, ascorbate peroxidase (APX), and glutathione reductase activities among various leaf ages in untreated plants. Induction of antioxidant activity in response to low temperature was higher in the youngest leaf than in the oldest leaf. Expression of APX isozymes increased in response to low temperature, and their expression was the highest in the youngest leaf. Current results support earlier findings that antioxidant protection also was a mechanism for paraquat tolerance.</jats:p>

Effects of the Protein Hydrolysate Pretreatment on Cucumber Plants Exposed to Chilling Stress

“…e extent of the damage caused by chilling stress depends on temperature, duration of exposure, plant developmental stage, and other factors (Borowski, 2009;Phansak et al, 2021). e most frequently reported chilling-provoked changes at the cellular level include alterations in gene expression, protein turnover, lipid and carbohydrate composition, membrane permeability, and solute leakage (Kuk & Shin, 2007). Some of these changes and damages can be attributed to chilling-induced oxidative stress in the plant cells (Gill & Tuteja, 2010;Lukatkin, 2002).…”

Effect of a Short-Term Daily Temperature Drop on the Cold Tolerance of Leaves of Different Age

“…Предположительно, более низкая способность к температурной адаптации у листьев, закончивших рост, может быть связана с более ограниченными, чем у активно растущих листьев, возможностями структурной перестройки . Однако в литературе наряду с данными, которые говорят о большей устойчивости молодых листьев [Schwemmle, Lange, 1959;Фельдман, Каменцева, 1963], имеются и другие, свидетельствующие о более высокой устойчивости листьев, завершивших рост [Трофимова, 1995;Kuk, Shin, 2007;Lim et al, 2014].…”

Cucumber (Cucumis sativus L.) Nitric Oxide Synthase Associated Gene1 (CsNOA1) Plays a Role in Chilling Stress

“…We previously used exogenous application of an NO donor to elucidate the role of NO under chilling stress in cucumber (Liu et al, 2011), a warm-season species that requires protection from cold temperatures (Kuk and Shin, 2007). However, the role of NO in chilling stress tolerance and the source(s) of endogenous NO in cucumber seedlings have still not been resolved and these questions are addressed in this current study.…”