Guangdong Ocean University, College of Coastal Agriculture Sciences, Zhanjiang, Guangdong, China.
South China Center of National Saline-tolerant Rice Technology Innovation Center, Zhanjiang, Guangdong, China.
PeerJ. 2023 Jan 23;11:e14673. doi: 10.7717/peerj.14673. eCollection 2023.
Prohexadione calcium (Pro-Ca), as a growth retardant, can effectively alleviate the damage of salt stress to plants. In order to explore the effects of NaCl stress on the physiological characteristics and panicle traits of rice plants as well as the alleviating effect of Pro-Ca at the booting stage, we performed pot experiments on two rice cultivars: conventional rice '' and hybrid rice ''. Rice plants were treated with 0.3% NaCl 48 hours after Pro-Ca (100 mg L) treatment to study the effects of Pro-Ca on the physiological characteristics of the leaves and panicles, as well as the panicle and yield traits of rice under salt stress. Our analysis indicated that NaCl treatment inhibited the morphological growth parameters and photosynthetic efficiency, destroyed the antioxidant defense systems of leaves and panicles, increased soluble protein and proline in both rice cultivars. Foliar application of Pro-Ca significantly increased the leaf area, uppermost internode length, panicle length, panicle weight, number of primary branches, number of grains per panicle, seed setting rate and yield under salt stress. Pro-Ca application significantly affected chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and apparent mesophyll conductance (AMC) in NaCl-treated rice cultivars compared with NaCl treatment alone. Moreover, Pro-Ca also increased ascorbic acid (AsA) content, enhanced superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activity, and further increased the accumulation of soluble protein and proline in leaves and panicles. These results illustrated that foliar application of Pro-Ca at the booting stage could alleviate the damage caused by NaCl stress by regulating the physiological and metabolic processes of rice plants, thereby enhancing the stress resistance of the plants, increasing total rice yield in salt stress conditions.
丙环唑钙（Pro-Ca）作为一种生长抑制剂，能有效缓解盐胁迫对植物的伤害。为了探讨盐胁迫对水稻叶片生理特性和穗部性状的影响，以及 Pro-Ca 在孕穗期的缓解作用，我们在两个水稻品种上进行了盆栽试验：常规稻“”和杂交稻“”。在 Pro-Ca（100mgL）处理后 48 小时，用 0.3%NaCl 处理水稻植株，研究 Pro-Ca 对盐胁迫下叶片和穗部生理特性以及水稻穗部和产量性状的影响。结果表明，NaCl 处理抑制了形态生长参数和光合效率，破坏了叶片和穗的抗氧化防御系统，增加了两个水稻品种的可溶性蛋白和脯氨酸含量。叶面喷施 Pro-Ca 可显著提高盐胁迫下水稻的叶面积、最上节间长、穗长、穗重、一次枝梗数、穗粒数、结实率和产量。与单独用 NaCl 处理相比，Pro-Ca 处理显著影响了 NaCl 处理水稻品种的叶绿素含量、净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）和表观叶肉导度（AMC）。此外，Pro-Ca 还增加了抗坏血酸（AsA）含量，增强了超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的活性，进一步增加了叶片和穗部可溶性蛋白和脯氨酸的积累。这些结果表明，孕穗期叶面喷施 Pro-Ca 可以通过调节水稻植株的生理代谢过程来缓解 NaCl 胁迫造成的伤害，从而增强植物的抗逆性，增加盐胁迫条件下水稻的总产量。
