The Halophyte Seashore Paspalum Uses Adaxial Leaf Papillae for Sodium Sequestration
The Halophyte Seashore Paspalum Uses Adaxial Leaf Papillae for Sodium Sequestration
复制标题
DOI：
10.1104/pp.20.00796
复制
发表时间：
2020-12-01
期刊：
影响因子：
7.4
通讯作者：
Devos, Katrien M.
中科院分区：
文献类型：
--
作者：
Spiekerman, John J.;Devos, Katrien M.
盐生草坪草海滨雀稗螯合钠在近轴叶乳头，提供证据的存在下，Panicoideae草亚科的功能螯合结构。盐碱化是全球范围内日益严重的问题，预计在未来30年内，由于土壤盐碱化，将有近30%的可耕地消失。许多对维持世界热量摄入至关重要的禾本科作物对盐敏感。研究盐生禾草的耐盐机制，可能是最终改良盐敏感性禾草作物的有效途径。海滨雀鲷（Paspalum vaginatum）是一种盐生植物Panicoid草，能够在接近海水的盐浓度下生长。尽管其作为一种可持续的草坪草被广泛种植，但其在光合组织中保持高Na+浓度同时保持生长的能力的机制仍然未知。为了更好地了解品种HI 10的上级耐盐性，我们研究了在盐条件下生长增加的P.vaginatum 'HI 10'和在盐条件下生长减少的Paspalum distichum 'Spence'的叶片结构和离子含量。品种HI 10和品种Spence之间的显著差异是品种HI 10中K+的高稳态水平。成像进一步表明，近轴面的两个品种HI 10和品种斯宾塞包含密集的肋脊的乳头。然而，这些表皮的单细胞扩展显着大于在CV HI 10比在CV斯宾塞。CV HI 10乳头被证明是作为Na+水槽植物生长在盐水条件下。我们提供的证据表明，叶乳头功能的Na+螯合在P. vaginatum专门的结构，说明了一个可能的途径，盐敏感的Panicoid作物具有类似的叶结构的生物技术改进。
The halophytic turfgrass seashore paspalum sequesters sodium in adaxial leaf papillae, providing evidence for the presence of functioning sequestration structures in the Panicoideae grass subfamily. Salinity is a growing issue worldwide, with nearly 30% of arable land predicted to be lost due to soil salinity in the next 30 years. Many grass crops that are vital to sustain the world's caloric intake are salt sensitive. Studying mechanisms of salt tolerance in halophytic grasses, plants that thrive in salt conditions, may be an effective approach to ultimately improve salt-sensitive grass crops. Seashore paspalum (Paspalum vaginatum) is a halophytic Panicoid grass able to grow in salt concentrations near that of seawater. Despite its widespread cultivation as a sustainable turfgrass, the mechanism underlying its ability to retain high Na+ concentrations in photosynthetic tissue while maintaining growth remains unknown. We examined the leaf structure and ion content in P. vaginatum 'HI10', which shows increased growth under saline conditions, and Paspalum distichum 'Spence', which shows reduced growth under salt, to better understand the superior salt tolerance of cv HI10. A striking difference between cv HI10 and cv Spence was the high steady-state level of K+ in cv HI10. Imaging further showed that the adaxial surface of both cv HI10 and cv Spence contained dense costal ridges of papillae. However, these unicellular extensions of the epidermis were significantly larger in cv HI10 than in cv Spence. The cv HI10 papillae were shown to act as Na+ sinks when plants were grown under saline conditions. We provide evidence that leaf papillae function as specialized structures for Na+ sequestration in P. vaginatum, illustrating a possible path for biotechnological improvement of salt-sensitive Panicoid crops with analogous leaf structures.