Tian Haoqi, Zhou Qingping, Liu Wenhui, Zhang Jing, Chen Youjun, Jia Zhifeng, Shao Yuqiao, Wang Hui
Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, Southwest Minzu University, Chengdu, China.
Academy of Animal Science and Veterinary Medicine of Qinghai Province, Xining, China.
Front Plant Sci. 2022 Jul 28;13:917528. doi: 10.3389/fpls.2022.917528. eCollection 2022.
Raising crops production improving photosynthesis has always been focused. Recently excavating and increasing the photosynthetic capacity of non-leaf organs becomes an important approach to crops yield increase. Here we studied the photosynthetic characteristics of the flag leaf and the non-leaf organs including the sheath, the glume and the lemma under greenhouse. The relative water content (RWC), the stomatal characteristics, the photosynthetic pigment contents, the enzyme activities in C and C pathway and the malate content of the flag leaf and the non-leaf organs on 7, 14, 21, and 28 days after anthesis (denoted by 7DAA, 14DAA, 21DAA, and 28DAA) were determined under well-watered (CK) and water-stressed (D) treatments. Drought stress significantly reduced the RWC of the flag leaf and the non-leaf organs, while the variation of RWC in the glume and the lemma was lower than in the flag leaf. The chlorophyll a content, the chlorophyll b content, the total chlorophyll content and the xanthophyll content in the flag leaf were significantly decreased under D. However, drought stress significantly increased the photosynthetic pigment contents in the glume at the late stage (21DAA and 28DAA). In addition, the induced activities of PEPC, NADP-MDH, NADP-ME, NAD-ME, and PPDK in non-leaf organs under drought stress suggested that the C photosynthetic pathway in non-leaf organs compensated the limited C photosynthesis in the flag leaf. Non-leaf organs, in particular the glume, showed the crucial function in maintaining the stable photosynthetic performance of oat.
提高作物产量、改善光合作用一直是研究重点。近年来，挖掘和提高非叶器官的光合能力成为提高作物产量的重要途径。本文研究了温室条件下旗叶以及包括叶鞘、颖片和外稃在内的非叶器官的光合特性。测定了花后7天、14天、21天和28天（分别记为7DAA、14DAA、21DAA和28DAA）时，在充分供水（CK）和水分胁迫（D）处理下旗叶和非叶器官的相对含水量（RWC）、气孔特性、光合色素含量、C3和C4途径中的酶活性以及苹果酸含量。干旱胁迫显著降低了旗叶和非叶器官的RWC，而颖片和外稃中RWC的变化低于旗叶。在水分胁迫下，旗叶中的叶绿素a含量、叶绿素b含量、总叶绿素含量和叶黄素含量显著降低。然而，干旱胁迫在后期（21DAA和28DAA）显著提高了颖片中的光合色素含量。此外，干旱胁迫下非叶器官中PEPC、NADP-MDH、NADP-ME、NAD-ME和PPDK的诱导活性表明，非叶器官中的C4光合途径补偿了旗叶中有限的C3光合作用。非叶器官，尤其是颖片，在维持燕麦稳定的光合性能方面发挥了关键作用。
