Elevated CO2 alleviates the negative impact of heat stress on wheat physiology but not on grain yield
Elevated CO2 alleviates the negative impact of heat stress on wheat physiology but not on grain yield
复制标题
DOI：
10.1093/jxb/erz386
复制
发表时间：
2019-11-01
影响因子：
6.9
通讯作者：
Ghannoum, Oula
中科院分区：
文献类型：
--
作者：
Chavan, Sachin G.;Duursma, Remko A.;Ghannoum, Oula
炎热的天气变得更加炎热和频繁，威胁着世界各地的小麦产量。开发为未来气候做好准备的小麦品种需要更好地理解高二氧化碳(ECO(2))和热胁迫(HS)如何交互影响小麦产量。我们在温室22/15摄氏度(昼夜)保持22/15摄氏度的温室里，在大气二氧化碳(ACO(2)，L L(-1))或ECO(2)(L L(-1))下种植了一个现代高产小麦品种(SCOUT)。一半的植株在开花时暴露在HS(40/24摄氏度)下5d。在非HS植物中，ECO(2)提高了(+36%)CO2同化速率(A(Sat))，尽管光合作用能力下调。HS降低了ACO(2)植株的A(Sat)(-42%)，但对ECO(2)植株没有影响，因为ECO(2)通过增加二磷酸核酮糖的再生能力和减少HS下的光化学伤害来保护光合作用。ECO(2)对所有植株的生物量(+35%)和非HS植株的籽粒产量(+30%)都有促进作用。植物生物量在HS后开始下降，但由于分蘖较晚，在成熟时恢复。在ACO(2)和ECO(2)种植的植株中，HS同样降低了籽粒产量(-40%)，原因是籽粒败育和籽粒灌浆减少。ECO(2)缓解了开花期HS对小麦光合作用和生物量的负面影响，但HS降低了两个CO2处理的籽粒产量。
Hot days are becoming hotter and more frequent, threatening wheat yields worldwide. Developing wheat varieties ready for future climates calls for improved understanding of how elevated CO2 (eCO(2)) and heat stress (HS) interactively impact wheat yields. We grew a modern, high-yielding wheat cultivar (Scout) at ambient CO2 (aCO(2), 419 mu l l (-1)) or eCO(2) (654 mu l l(-1)) in a glasshouse maintained at 22/15 degrees C (day/night). Half of the plants were exposed to HS (40/24 degrees C) for 5 d at anthesis. In non-HS plants, eCO(2) enhanced (+36%) CO2 assimilation rates (A(sat)) measured at growth CO2 despite down-regulation of photosynthetic capacity. HS reduced A(sat) (-42%) in aCO(2)- but not in eCO(2)-grown plants because eCO(2) protected photosynthesis by increasing ribulose bisphosphate regeneration capacity and reducing photochemical damage under HS. eCO(2) stimulated biomass (+35%) of all plants and grain yield (+30%) of non-HS plants only. Plant biomass initially decreased following HS but recovered at maturity due to late tillering. HS equally reduced grain yield (-40%) in aCO(2)- and eCO(2)-grown plants due to grain abortion and reduced grain filling. While eCO(2) mitigated the negative impacts of HS at anthesis on wheat photosynthesis and biomass, grain yield was reduced by HS in both CO2 treatments.