Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing Botanical Garden, Mem. Sun Yat-Sen, Nanjing 210014, Jiangsu, PR China.
Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing Botanical Garden, Mem. Sun Yat-Sen, Nanjing 210014, Jiangsu, PR China.
Plant Physiol Biochem. 2018 May;126:1-10. doi: 10.1016/j.plaphy.2018.02.018. Epub 2018 Feb 19.
Salinity is one of the major abiotic environmental stress factors affecting plant growth and development. Centipedegrass (Eremochloa ophiuroides [Munro)] Hack.) is an important warm-season turfgrass species with low turf maintenance requirements, but is sensitive to salinity stress. To explore salt tolerant germplasms in centipedegrass and better understand the growth and physiological responses of centipedegrass to salinity, we conducted anatomic observation and phytochemical quantification, examined growth parameters, and investigated photosynthetic machinery and antioxidant system in two phenotypically distinct centipedegrass accessions under NaCl salt stress. The morphophenotypical difference of the stems in the two accessions mainly depends on whether or not a thickened epidermal horny layer with purple colour was formed, which was caused by anthocyanin accumulation in the tissue. Successive salinity treatment was found to result in an inhibition of leaf growth, a marked decrease in photosynthesis, chlorophyll contents, and the maximal photochemical efficiency of PSII (Fv/Fm). Under the same treatment, purple-stem accession (E092) showed a lower degree of inhibition or decrease than green-stem one (E092-1). With the exception of malondialdehyde level, both proline content and antioxidant enzymes were upregulated to a greater extent in E092 following exposure to salinity condition. Meanwhile, significant enhancements of anthocyanin accumulation and total protein synthesis were detected in E092 after salt treatment, but not in E092-1. These results demonstrated that E092 favor better accumulation of anthocyanins under salinity condition, which contribute to salt tolerance by adjusting physiological functions and osmotic balance, and better maintenance of high turf quality. Hence, genetic phenotype can be utilized as a key indicator in E. ophiuroides breeding for salt-tolerance.
盐度是影响植物生长和发育的主要非生物环境胁迫因素之一。蜈蚣草（Eremochloa ophiuroides [Munro)] Hack.）是一种重要的暖季草坪草，具有低草坪维护要求，但对盐胁迫敏感。为了探索蜈蚣草的耐盐种质资源，更好地了解蜈蚣草对盐胁迫的生长和生理响应，我们对两个表型不同的蜈蚣草品系进行了解剖观察和植物化学定量分析，研究了生长参数，并研究了在 NaCl 盐胁迫下两个蜈蚣草品系的光合机构和抗氧化系统。两个品系茎的形态表型差异主要取决于是否形成了增厚的表皮角质层，其颜色为紫色，这是由于组织中花青素的积累。连续盐处理导致叶片生长受到抑制，光合作用、叶绿素含量和 PSII 的最大光化学效率（Fv/Fm）显著下降。在相同处理下，紫色茎品系（E092）比绿色茎品系（E092-1）的抑制或减少程度较低。除了丙二醛水平外，E092 在暴露于盐胁迫条件下，脯氨酸含量和抗氧化酶的表达水平均上调到更高程度。同时，在盐处理后，E092 中检测到显著增加的花青素积累和总蛋白合成，但在 E092-1 中没有。这些结果表明，E092 在盐胁迫条件下有利于更好地积累花青素，通过调节生理功能和渗透平衡以及更好地维持高草坪质量来提高耐盐性。因此，遗传表型可以作为 E. ophiuroides 耐盐性育种的关键指标。
