PHOTOSYNTHETICA

Photosynthetica 2019, 57(3):830-840 | DOI: 10.32615/ps.2019.086

Long-term high light stress induces leaf senescence in wheat (Triticum aestivum L.)

Y.N. LIU^1,2, Q.Z. XU^1,3, W.C. LI², X.H. YANG³, Q. ZHENG¹, B. LI¹, Z.S. LI¹, H.W. LI¹

¹ State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, 100101 Beijing, China

² College of Life Sciences, Henan Normal University, Xinxiang 453007, Henan, China

³ Key Laboratory of Crop Biology, Shandong Agricultural University, 271018 Taian, China

In order to explore the association of long-term high light (HL) with leaf senescence in wheat, two wheat genotypes Xiaoyan 54 (HL-tolerant) and Jing 411 (HL-sensitive) grown in low light were subjected to HL for 2-8 d. The results showed that 6-8 d of HL led to dramatic decline of chlorophyll content, photochemical efficiency, and activity of Rubisco and antioxidant enzymes. Meanwhile, the content of malondialdehyde (MDA), soluble proteins, soluble sugars, superoxide anion, and ascorbic acid increased markedly. Additionally, the expression of senescence-associated genes (SAGs) was induced by HL. Xiaoyan 54 accumulated less MDA, soluble sugars, and superoxide anions but showed a higher ratio of reduced to oxidized ascorbic acid than that in Jing 411 under long-term HL stress. Moreover, most of the assayed SAGs were less induced in Xiaoyan 54 than that in Jing 411. Altogether, the reduction of antioxidant enzyme activities and accumulation of soluble sugars may result in long-term HL-induced leaf senescence.

Received: August 23, 2018; Accepted: November 21, 2018; Prepublished online: July 9, 2019; Published: July 23, 2019  Show citation