Soil Silicon Amendment Increases Phyllostachys praecox Cold Tolerance in a Pot Experiment

Abstract

Cultivated bamboos are occasionally subjected to cold stress in winter, and silicon could improve their cold tolerance. However, evidence of the effect of Si on bamboos is still limited. Therefore, a batch and pot experiment was conducted for six months to investigate the effects of different Si fertilizer application rates (0, 0.5, 1.0, 2.0, 4.0, and 8.0 g kg−1 of soil weight) on the physiological responses and photosynthesis parameters of Phyllostachys praecox under a simulated cold stress condition. The cold temperature was set to 5 °C, 0 °C, and −5 °C, successively. The bamboo biomass increased significantly when the Si amendment rate was at least 2.0 g kg−1 (P = 0.002), and the highest biomass increase and root-to-canopy ratio were obtained with the 4.0 g kg−1 Si amendment. Furthermore, the Si contents in all organs of the bamboos increased with the increase of the Si amendment rate. The highest content of Si among the other organs was observed in the leaf, and the content was 68.95 mg kg−1 with the treatment of 4.0 g kg−1. With the application of Si, the photosynthesis rate of bamboo leaves was significantly increased (P = 0.008). The Si-amended bamboo exhibited a cold tolerance that was associated with stimulating antioxidant systems, and the enzyme activities of superoxide dismutase, peroxidase, and catalase increased with the increase of the Si amendment rate, whereas the malondialdehyde content and cell membrane permeability decreased with all Si treatments. A low temperature of −5 °C exerted effects on the bamboo leaf chloroplasts, but the ultrastructures of the chloroplasts remained intact after Si treatment. These findings suggest that Si fertilizer enhances bamboo growth and the tolerance of bamboo plants to cold stress. However, a high application rate (8.0 g kg−1) caused a decline in the bamboo biomass, compared to T4. Thus, a Si fertilization rate of 2.0~8.0 g kg−1 is recommended for bamboos under cold conditions.

Multidimensional Role of Silicon to Activate Resilient Plant Growth and to Mitigate Abiotic Stress

“…Subsequently, the overexpression of OsDREB1 was reported to enhance tolerance to chilling and drought stress ( Ito et al, 2006 ). Qian et al (2019) reported that Si induced cold tolerance in Phyllostachys praecox by stimulating the activities of CAT, SOD, and POD during cold stress.…”

The silicon regulates microbiome diversity and plant defenses during cold stress in Glycine max L.

“…In synergy, cold stress causes cellular desiccation and osmotic imbalance – enhancing expression patterns of ABA-related genes. GmNCED3 – major ABA biosynthesis-related gene, we found a 4.8-fold gene expression pattern in cold stress, significantly reduced (2.5 fold) in Si with cold stress ( Qian et al., 2019 ). The ABA-receptor proteins ABAR1 and ABAR2 genes are involved in ABA biosynthesis and the circadian clock ( Rane et al., 2021 ).…”

“…We observed significantly higher CAT activity in cold treatment than in control, whereas the Si application significantly reduced it during cold stress. A similar example of Phyllostachys praecox is highly susceptible to cold stress and exhibits elevated SOD, CAT, and POD activities with the Si treatment ( Qian et al., 2019 ). Similarly, the SOD, POD, and PPO activities were higher in cold stress than in control, where the activities of the enzymes were reduced significantly in Si with a cold treatment ( Prasad, 1997 ; Møller et al., 2007 ; Si et al., 2018 ; Tripathi et al., 2022 ) – revealing reducing low-temperature stress effects ( Sharifi et al., 2022 ).…”

Physiological Responses to Abiotic and Biotic Stress in Forest Trees

“…Among the eighteen papers published, seventeen covered drought or salt stress as major environmental cues, highlighting the relevance of this topic in times of climate change. Only one paper studied cold stress [1]. The dominance of drought and salt stress studies underpins the need to understand tree responses to these environmental threats from the molecular to the ecophysiological level.…”

“…The papers contributing to this Special Issue cover these scientific aspects in different areas of the globe and encompass conifers as well as broadleaf tree species. In addition, two studies deal with bamboo (Phyllostachys sp., [1,2]). Bamboo, although botanically belonging to grasses, was included because its ecological functions and applications are similar to those of trees.…”