Root cortical aerenchyma improves the drought tolerance of maize (Zea mays L.)
Root cortical aerenchyma improves the drought tolerance of maize (Zea mays L.)
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DOI：
10.1111/j.1365-3040.2009.02099.x
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发表时间：
2010-05-01
影响因子：
7.3
通讯作者：
Lynch, Jonathan P.
中科院分区：
文献类型：
--
作者：
Zhu, Jinming;Brown, Kathleen M.;Lynch, Jonathan P.
根皮层通气组织 (RCA) 通过将活皮层组织转化为空气量来减少玉米的根部呼吸。我们假设 RCA 通过降低根系代谢成本、允许更大的根系生长和从干燥土壤中获取水分来提高耐旱性。为了验证这一假设，在田间和温室土壤中层环境中的水分胁迫下观察了具有高和低 RCA 的重组自交系。在田间，与低 RCA 品系相比，在水分胁迫下，高 RCA 品系在开花时的枝条生物量高出 30%。与低 RCA 品系相比，高 RCA 品系在深层土壤中的根长密度显着更大。在水分胁迫下，高 RCA 品系的中午叶片相对含水量比低 RCA 品系高 10%。在水分胁迫下，高 RCA 品系的平均产量是低 RCA 品系的八倍。在中生态系统中，与低 RCA 品系相比，在水分胁迫下，高 RCA 品系具有较少的精根呼吸、更深的生根和更大的地上部生物量。这些结果支持了这样的假设：RCA 通过降低土壤勘探的代谢成本而有利于玉米的耐旱性。
Root cortical aerenchyma (RCA) reduces root respiration in maize by converting living cortical tissue to air volume. We hypothesized that RCA increases drought tolerance by reducing root metabolic costs, permitting greater root growth and water acquisition from drying soil. To test this hypothesis, recombinant inbred lines with high and low RCA were observed under water stress in the field and in soil mesocosms in a greenhouse. In the field, lines with high RCA had 30% more shoot biomass at flowering compared with lines with low RCA under water stress. Root length density in deep soil was significantly greater in the high RCA lines compared with the low RCA lines. Mid-day leaf relative water content in the high RCA lines was 10% greater than in the low RCA lines under water stress. The high RCA lines averaged eight times the yield of the low RCA lines under water stress. In mesocosms, high RCA lines had less seminal root respiration, deeper rooting, and greater shoot biomass compared with low RCA lines under water stress. These results support the hypothesis that RCA is beneficial for drought tolerance in maize by reducing the metabolic cost of soil exploration.