Balance between salt stress and endogenous hormones influence dry matter accumulation in Jerusalem artichoke.
Salinity is one of the most serious environmental stresses limiting agricultural production. Production of Jerusalem artichoke on saline land is strategically important for using saline land resources. The interaction between plant hormones and salinity stress in governing Jerusalem artichoke (Helianthus tuberosus) growth is unclear. Jerusalem artichoke (variety Nanyu-1) was grown under variable salinity stress in the field, and a role of endogenous hormones [zeatin (ZT), auxins (IAA), gibberellins (GA3) and abscisic acid (ABA)] in regulating sugar and dry matter accumulation in tubers was characterized. Under mild salt stress (≤2.2gNaClkg(-1) soil), Nanyu-1 grew well with no significant alteration of dry matter distribution to stems and tubers. In contrast, under moderate salt stress (2.7gNaClkg(-1) soil), the distribution to stem decreased and to tubers decreased significantly. Mild salt stress induced sugar accumulation in tubers at the beginning of the tuber-expansion period, but significantly inhibited (i) transfer of non-reducing sugars to tubers, and (ii) polymerization and accumulation of fructan during the tuber-expansion stage. Under different salinity stress, before the stolon growth, the ratio of IAA/ABA in leaves increased significantly and that of GA3/ABA increased slightly; during tuber development, these ratios continued to decrease and reached the minimum late in the tuber-expansion period. While, salt stress inhibited (i) underground dry matter accumulation, (ii) tuber dry matter accumulation efficiency, (iii) transport of non-reducing sugars to tubers, and (iv) fructan accumulation efficiency during the tuber-expansion period; these effects were accompanied by significantly decreased tuber yield with an increase in salinity. With soil salinity increasing, the synthesis of IAA and GA3 was inhibited in leaves and tubers, while ABA synthesis was stimulated. In brief, tuber yield would significantly decreased with the increase of salinity.
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Tianyun
T
Shao
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Lingling
L
Li
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Yawen
Y
Wu
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Manxia
M
Chen
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: longxiaohua@njau.edu.cn.
Xiaohua
X
Long
Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; Institute of Agro-biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China. Electronic address: shaohongbochu@126.com.
Hongbo
H
Shao
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Zhaopu
Z
Liu
Soil Science and Plant Nutrition, School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
Zed
Z
Rengel
D018533:Biomass; D006368:Helianthus / Q000254:growth & development* / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D035281:Plant Tubers / Q000254:growth & development / Q000378:metabolism; D054712:Salinity; D013312:Stress, Physiological; D000073893:Sugars / Q000378:metabolism*
D010937:Plant Growth Regulators; D000073893:Sugars
Dry matter; Endogenous phytohormones; Jerusalem artichoke; Salt stress; Tuber