盐度是影响植物生长的最重要的生态限制之一。这对全球农业构成了毁灭性的威胁。在胁迫条件下产生的剩余数量的ROS通过破坏细胞成分对植物的生长和存活有负面影响,包括核酸,脂质,蛋白质和碳水化合物。然而,低水平的ROS也是必需的,因为它们在各种发育相关途径中作为信号分子。植物具有复杂的抗氧化系统,用于清除和调节ROS水平,以保护细胞免受损害。脯氨酸是抗氧化剂机制的一种重要的非酶渗透物,可以减轻压力。对提高容忍度有广泛的研究,有效性,保护植物免受压力,到目前为止,各种物质已被用来减轻盐的不利影响。在本研究中,锌(Zn)用于阐明其对小米脯氨酸代谢和应激反应机制的影响。我们的研究结果表明,随着NaCl处理的增加,对生长发育的负面影响。然而,低剂量的外源锌被证明有助于通过改善形态和生化特征来减轻NaCl的影响。在盐处理的植物中,低剂量的锌(1mg/L,2mg/L)挽救了盐(150mM)的负面影响,芽长度(SL)增加了7.26%和25.5%,根长(RL)分别为21.84%和39.07%,膜稳定性指数(MSI)分别为132.57%和151.58%。在所有浓度下,脯氨酸含量均有所提高,在2mg/LZn下最大增加66.65%。同样,低剂量的锌也挽救了盐在200mMNaCl诱导的胁迫。在较低剂量的Zn下,与脯氨酸生物合成相关的酶也得到了改善。在盐处理的植物(150mM),锌(1毫克/升,2mg/L)使P5CS的活性分别提高了19.344%和21%。在2mg/LZn下,P5CR和OAT活性也得到了改善,分别最大增加了21.66%和21.84%。同样,低剂量的锌也增加了P5CS的活性,P5CR和OAT在200mMNaCl。而P5CDH酶活性在2mg/LZn150mMNaCl时降低了82.5%,在2mg/LZn200mMNaCl时降低了56.7%。这些结果强烈暗示了Zn在NaCl胁迫期间维持脯氨酸库的调节作用。
Salinity is one of the most concerning ecological restrictions influencing plant growth, which poses a devastating threat to global agriculture. Surplus quantities of ROS generated under stress conditions have negative effects on plants\' growth and survival by damaging cellular components, including nucleic acids, lipids, proteins and carbohydrates. However, low levels of ROS are also necessary because of their role as signalling molecules in various development-related pathways. Plants possess sophisticated antioxidant systems for scavenging as well as regulating ROS levels to protect cells from damage. Proline is one such crucial non-enzymatic osmolyte of antioxidant machinery that functions in the reduction of stress. There has been extensive research on improving the tolerance, effectiveness, and protection of plants against stress, and to date, various substances have been used to mitigate the adverse effects of salt. In the present study Zinc (Zn) was applied to elucidate its effect on proline metabolism and stress-responsive mechanisms in proso millet. The results of our study indicate the negative impact on growth and development with increasing treatments of NaCl. However, the low doses of exogenous Zn proved beneficial in mitigating the effects of NaCl by improving morphological and biochemical features. In salt-treated plants, the low doses of Zn (1 mg/L, 2 mg/L) rescued the negative impact of salt (150mM) as evidenced by increase in shoot length (SL) by 7.26% and 25.5%, root length (RL) by 21.84% and 39.07% and membrane stability index (MSI) by 132.57% and 151.58% respectively.The proline content improved at all concentrations with maximum increase of 66.65% at 2 mg/L Zn. Similarly, the low doses of Zn also rescued the salt induced stress at 200mM NaCl. The enzymes related to proline biosynthesis were also improved at lower doses of Zn. In salt treated plants (150mM), Zn (1 mg/L, 2 mg/L) increased the activity of
P5CS by 19.344% and 21%. The P5CR and OAT activities were also improved with maximum increase of 21.66% and 21.84% at 2 mg/L Zn respectively. Similarly, the low doses of Zn also increased the activities of
P5CS, P5CR and OAT at 200mM NaCl. Whereas P5CDH enzyme activity showed a decrease of 82.5% at 2mg/L Zn+150mM NaCl and 56.7% at 2mg/L Zn+200 mM NaCl. These results strongly imply the modulatory role of Zn in maintaining of proline pool during NaCl stress.