TY - JOUR
T1 - Light intensity influence maize adaptation to low P stress by altering root morphology
AU - Zhou, Tao
AU - Wang, Li
AU - Sun, Xin
AU - Wang, Xiaochun
AU - Chen, Yinglong
AU - Rengel, Zed
AU - Liu, Weiguo
AU - Yang, Wenyu
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Background and aims
Soil phosphorus (P) availability, as well as shoot P status, may alter root morphology. However, how root morphological traits to light intensity under various P environments remains unknown.
Methods
Maize (Zea mays L.) cultivar CD418 grew under nine P application rates (ranged from 0 to 300 mg P kg−1 soil, supplied as KH2PO4) under natural light intensity (NL) and low light intensity (LL, 40% of natural light intensity) in a naturally-lit rain-shed. Plant growth, P uptake, and responses of root morphological traits (i.e. total root length, root surface area, and proportion of <0.2 mm diameter fine root) in the light and P treatments were assessed after 36 d of growth (five-leaf stage).
Results
Shoot and root dry weights increased under the natural light intensity in all P treatments. The ratio of root to shoot dry weight increased under NL when the soil Olsen-P was below 15.9 mg kg−1. At relatively low soil P availability (6.7 to 15.9 mg kg−1), total root length, root surface area, and fine root percentage were enhanced with increases in light intensity from LL to NL. These effects diminished in soil with either severely low P (2.6 mg kg−1) or excess P (above 20.6 mg kg−1). Express of the low P-tolerance transcription factor ZmPTF1 (that influences root growth by regulating carbon metabolism in leaves and roots), P uptake, and fertilizer P use efficiency were higher under NL than LL, especially under low P conditions (Olsen-P 6.7–15.9 mg kg−1). Increased responses of root morphological traits to low P conditions were associated with relatively low P concentrations in the leaves and high sucrose concentrations in the roots.
Conclusions
Compared to LL, under P deficiency and NL conditions, maize allocated more photosynthates to roots as sucrose, which acts as a low-P signal; in addition, sucrose as a carbon and energy source stimulated root growth and, consequently, adaptation of maize to low P stress.
AB - Background and aims
Soil phosphorus (P) availability, as well as shoot P status, may alter root morphology. However, how root morphological traits to light intensity under various P environments remains unknown.
Methods
Maize (Zea mays L.) cultivar CD418 grew under nine P application rates (ranged from 0 to 300 mg P kg−1 soil, supplied as KH2PO4) under natural light intensity (NL) and low light intensity (LL, 40% of natural light intensity) in a naturally-lit rain-shed. Plant growth, P uptake, and responses of root morphological traits (i.e. total root length, root surface area, and proportion of <0.2 mm diameter fine root) in the light and P treatments were assessed after 36 d of growth (five-leaf stage).
Results
Shoot and root dry weights increased under the natural light intensity in all P treatments. The ratio of root to shoot dry weight increased under NL when the soil Olsen-P was below 15.9 mg kg−1. At relatively low soil P availability (6.7 to 15.9 mg kg−1), total root length, root surface area, and fine root percentage were enhanced with increases in light intensity from LL to NL. These effects diminished in soil with either severely low P (2.6 mg kg−1) or excess P (above 20.6 mg kg−1). Express of the low P-tolerance transcription factor ZmPTF1 (that influences root growth by regulating carbon metabolism in leaves and roots), P uptake, and fertilizer P use efficiency were higher under NL than LL, especially under low P conditions (Olsen-P 6.7–15.9 mg kg−1). Increased responses of root morphological traits to low P conditions were associated with relatively low P concentrations in the leaves and high sucrose concentrations in the roots.
Conclusions
Compared to LL, under P deficiency and NL conditions, maize allocated more photosynthates to roots as sucrose, which acts as a low-P signal; in addition, sucrose as a carbon and energy source stimulated root growth and, consequently, adaptation of maize to low P stress.
UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85071470251&origin=resultslist&sort=plf-f&src=s&st1=10.1007%2fs11104-019-04259-8&st2=&sid=cb53c2e6ec9aa5afa023b211ee40cd4a&sot=b&sdt=b&sl=31&s=DOI%2810.1007%2fs11104-019-04259-8%29&relpos=0&citeCnt=0&searchTerm=
U2 - 10.1007/s11104-019-04259-8
DO - 10.1007/s11104-019-04259-8
M3 - Article
SN - 0032-079X
VL - 447
SP - 183
EP - 197
JO - Plant and Soil: An International Journal on Plant-Soil Relationships
JF - Plant and Soil: An International Journal on Plant-Soil Relationships
IS - 1-2
ER -