摘要
磷酸烯醇式丙酮酸羧化酶(PEPC)是C_(4)光合关键酶,有助于植物在非生物胁迫下抵御逆境。异子蓬(Suaeda aralo-caspica)是一种无须Kranz结构即可在单细胞中高效执行C_(4)光合作用的荒漠盐生植物,在C 3作物遗传改良方面具有天然优势。以转异子蓬SaPEPC2基因烟草(Nicotiana tabacum)为材料,探讨了其抗旱功能和光合性能。结果表明,过表达SaPEPC2提高了烟草叶片持水能力,可保持叶绿素稳定;积累更多的渗透调节物质,增强了抗氧化酶活性,进而降低了植株体内的活性氧水平,减轻膜损伤程度;同时还增强了烟草抗旱相关基因和内源光合基因的表达,提高了PEPC活性和净光合速率,可能是促进了烟草体内的“类C_(4)微循环”途径所致。研究结果为进一步利用异子蓬单细胞C_(4)途径PEPC基因培育高光效抗逆农作物品种奠定了基础。
INTRODUCTION:Phosphoenolpyruvate carboxylase(PEPC)is a key enzyme for C_(4) photosynthesis that help plants to resist adversity under abiotic stress.Suaeda aralocaspica,an annual halophyte,has gradually developed a single-cell C_(4) photosynthetic pathway by compartmentalizing a chlorenchyma cell into distal and proximal ends to delineate and form the four-carbon(C_(4))and three-carbon(C_(3))cycles through long term of evolution.This unique biochemical compartment-ation pattern holds promise for introducing“C_(4)-like microcirculation”into C_(3) plants without establishing Kranz anatomy.RATIONALE:The PEPC gene act as an essential component of C_(4) photosynthesis,but few studies have reported on the PEPC gene in single cell C_(4)-pathway species.To reveal the impact of the SaPEPC2 gene from S.aralocaspica on the photosynthetic performance and drought resistance of C_(3) plants,we evaluated the drought resistance function and pho-tosynthetic performance of transgenic tobacco(Nicotiana tabacum)overexpressing the SaPEPC2 gene driven by its own promoter(ProSaPEPC2::SaPEPC2)through physiological measurements and gene expression analysis methods.RESULTS:Our findings demonstrated that overexpressing the SaPEPC2 gene in tobacco improved leaf water retention,maintained chlorophyll stability,promoted the accumulation of osmotic adjustment substance,enhanced antioxidant en-zyme activities,reduced ROS levels,mitigated the extent of membrane damage,upregulated the expression of drou-ght-related and endogenous photosynthesis genes,and increased PEPC enzyme activity and net photosynthetic rate.CONCLUSION:In conclusion,overexpressing the SaPEPC2 gene likely facilitates the formation of a“C_(4)-like microcircula-tion”pathway in tobacco.These results may provide the theoretical foundation for the potential utilization of the single-cell C_(4) pathway PEPC genes from S.aralocaspica to breed high light-efficiency and stress-resistant crop varieties.Overexpression of SaPEPC2 in tobacco results in stronger drought resistance a
作者
廖星鑫
牛祎
多兴武
阿克也得力·居玛哈孜
买热哈巴·阿不都克尤木
热孜瓦尼姑丽·胡甫尔
兰海燕
曹婧
Xingxin Liao;Yi Niu;Xingwu Duo;Akeyedeli Jumahazi;Marhaba Abdukuyum Rizwangul Hufur;Haiyan Lan;Jing Cao(National Demonstration Center for Experimental Biology Education,Xinjiang Key Laboratory of Biological Resources and Genetic Engineering,College of Life Sciences and Technology,Xinjiang University,Urumqi 830017,China)
出处
《植物学报》
CAS
CSCD
北大核心
2024年第4期585-599,共15页
Chinese Bulletin of Botany
基金
新疆维吾尔自治区自然科学基金(No.2022D01C95)
国家自然科学基金(No.32360066)
国家级大学生创新训练计划(No.202210755069)。
关键词
单细胞C
4植物
异子蓬
PEPC
抗旱性
光合作用
single-cell C4 plant
Suaeda aralocaspica
PEPC
drought resistance
photosynthesis
