Suppression of ROS generation mediated by higher InsP(3) level is critical for the delay of seed germination in lpa rice
Suppression of ROS generation mediated by higher InsP(3) level is critical for the delay of seed germination in lpa rice
复制标题
高 InsP(3) 水平介导的 ROS 生成抑制对于 lpa 水稻种子萌发的延迟至关重要
DOI：
10.1007/s10725-018-0402-8
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发表时间：
2018
影响因子：
4.2
通讯作者：
Cheng Fangmin
中科院分区：
文献类型：
--
作者：
Zhou Lujian;Ye Yu;Zhao Qian;Du Xiaoxia;Zakari Shamsu Ado;Su Da;Pan Gang;Cheng Fangmin
培育低植酸作物是改善作物营养状况的有效途径，但低植酸作物种子发芽性能较差。本文对两个水稻基因型，cv。以9311及其突变体9311-lpa为材料，研究了发芽种子中InsP 3和ROS浓度与旱莲草种子萌发延迟的关系。结果表明，9311-lpa种子萌发性能较差主要表现为种子萌发进程延迟，在较长的吸胀时间后，两种基因型的种子萌发率差异不显著。9311-lpa种子萌发延迟与其InsP 3和活性氧浓度的基因型差异密切相关，与野生型相比，9311-lpa的InsP 3水平显著升高，活性氧浓度显著降低。在适宜浓度范围内，外源H2 O2处理促进了种子萌发，而InsP 3激活剂（m-3 M3 FBS）对种子萌发有抑制作用。9311-lpa种子萌发延迟的主要原因是萌发种子中InsP 3水平较高和ROS浓度较低。此外，9311-lpa萌发种子的活性氧清除酶（SOD、CAT、POD和APX）和活性氧产生酶（NOX）活性均低于野生型，m-3 M3 FBS显著抑制了萌发种子的NOX活性和NOX转录，从而导致萌发种子中活性氧产生量降低，种子萌发率降低。因此，9311-lpa种子萌发受阻，且萌发种子中活性氧水平较低，主要是由于较高InsP 3水平下活性氧产生能力较弱所致，而不是种子萌发过程中活性氧爆发的有效解毒。
The breeding of low phytic acid (lpa) crop is considered as an effective strategy to improve crop nutrition, but these crops have an inferior performance in seed germination. In this paper, two rice genotypes,cv. 9311 and itslpamutant (9311-lpa), were used to clarify the relationship of InsP3and ROS concentration in sprouting seeds with the occurrence of retarded seed germination forlpacrop. Results showed that the inferior performance of seed germination for 9311-lpawas mostly characterized by the delay of seed germination progression, with insignificant difference in seed germination rate between the two genotypes after a longer imbibition duration. The retarded seed germination of 9311-lpawas closely associated with the genotypic difference in InsP3and ROS concentrations in germinating seeds, with the considerably higher InsP3level and lower ROS concentration for 9311-lparelative to the wild type. Under an appropriate range of concentration, exogenous H2O2treatment promoted seed germination, while the activator of InsP3(m-3M3FBS) had an inhibitory effect on seed germination. The delay of seed germination occurred mainly as the results of the higher InsP3level and the lower ROS concentration in the germinating seeds of 9311-lpa. Furthermore, the germinating seeds of 9311-lpahad relatively lower activities of ROS scavenging enzymes (SOD, CAT, POD, and APX) and ROS generating enzyme (NOX) than those of the wild type.m-3M3FBS significantly suppressed NOX activity and NOX transcripts in sprouting seeds, which then resulted in the lowered ROS generation in sprouting seeds and the decreased seed germination rate. Thus, the retarded seed germination of 9311-lpa, with lower ROS level in germinating seeds, was mostly caused by the weaker ability of ROS generation in the presence of higher InsP3level, rather than the effective detoxification of ROS burst during seed germination.