Li Guanghao, Li Wei, Liang Yuwen, Lu Weiping, Lu Dalei
Jiangsu Key Laboratory of Crop Genetics and Physiology, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.
Front Plant Sci. 2023 Jun 20;14:1220827. doi: 10.3389/fpls.2023.1220827. eCollection 2023.
Insufficient light during the growth periods has become one of the main factors restricting maize yield with global climate change. Exogenous hormones application is a feasible measure to alleviate abiotic stresses on crop productivity. In this study, a field trial was conducted to investigate the effects of spraying exogenous hormones on yield, dry matter (DM) and nitrogen (N) accumulation, leaf carbon and N metabolism of fresh waxy maize under weak-light stress in 2021 and 2022. Five treatments including natural light (CK), weak-light after pollination (Z), spraying water (ZP1), exogenous Phytase Q9 (ZP2) and 6-benzyladenine (ZP3) under weak-light after pollination were set up using two hybrids suyunuo5 (SYN5) and jingkenuo2000 (JKN2000). Results showed that weak-light stress significantly reduced the average fresh ear yield (49.8%), fresh grain yield (47.9%), DM (53.3%) and N accumulation (59.9%), and increased grain moisture content. The net photosynthetic rate (Pn), transpiration rate (Tr) of ear leaf after pollination decreased under Z. Furthermore, weak-light decreased the activities of RuBPCase and PEPCase, nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in ear leaves, and increased malondialdehyde (MDA) accumulation. And the decrease was greater on JKN2000. While ZP2 and ZP3 treatments increased the fresh ear yield (17.8%, 25.3%), fresh grain yield (17.2%, 29.5%), DM (35.8%, 44.6%) and N (42.5%, 52.4%) accumulation, and decreased grain moisture content compared with Z. The Pn, Tr increased under ZP2 and ZP3. Moreover, the ZP2 and ZP3 treatments improved the activities of RuBPCase, PEPCase; NR, GS, GOGAT; SOD, CAT, POD in ear leaves, and decreased MDA content during grain filling stage. The results also showed the mitigative effect of ZP3 was greater than ZP2, and the improvement effect was more significant on JKN2000.
随着全球气候变化，生长期间光照不足已成为限制玉米产量的主要因素之一。施用外源激素是缓解非生物胁迫对作物生产力影响的一种可行措施。本研究于2021年和2022年进行了田间试验，以探究授粉后弱光胁迫下喷施外源激素对鲜食糯玉米产量、干物质（DM）和氮（N）积累以及叶片碳氮代谢的影响。选用苏玉糯5号（SYN5）和京科糯2000（JKN2000）两个杂交种，设置了五个处理，包括自然光（CK）、授粉后弱光（Z）、授粉后弱光下喷水（ZP1）、外源植酸酶Q9（ZP2）和6-苄基腺嘌呤（ZP3）。结果表明，弱光胁迫显著降低了平均鲜穗产量（49.8%）、鲜粒产量（47.9%）、干物质（53.3%）和氮积累量（59.9%），并提高了籽粒含水量。在Z处理下，授粉后穗叶的净光合速率（Pn）、蒸腾速率（Tr）下降。此外，弱光降低了穗叶中核酮糖-1,5-二磷酸羧化酶（RuBPCase）、磷酸烯醇式丙酮酸羧化酶（PEPCase）、硝酸还原酶（NR）、谷氨酰胺合成酶（GS）、谷氨酸合酶（GOGAT）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）的活性，并增加了丙二醛（MDA）的积累。JKN2000的下降幅度更大。与Z处理相比，ZP2和ZP3处理增加了鲜穗产量（17.8%，25.3%）、鲜粒产量（17.2%，29.5%）、干物质（35.8%，44.6%）和氮（42.5%，52.4%）的积累量，并降低了籽粒含水量。ZP2和ZP3处理下Pn、Tr升高。此外，ZP2和ZP3处理提高了灌浆期穗叶中RuBPCase、PEPCase、NR、GS、GOGAT、SOD、CAT、POD的活性，并降低了MDA含量。结果还表明，ZP3的缓解效果大于ZP2，对JKN2000的改善效果更显著。
