How membranes organize during seed germination: three patterns of dynamic lipid remodelling define chilling resistance and affect plastid biogenesis

Abstract

Imbibitional chilling injury during germination causes agricultural losses but this can be overcome by osmopriming. It remains unknown how membranes reorganize during germination. Herein, we comparatively profiled changes of membrane lipids during imbibition under normal and chilling temperatures in chilling-tolerant and -sensitive soybean seeds. We found three patterns of dynamic lipid remodelling during the three phases of germination. Pattern 1 involved a gradual increase in plastidic lipids during phases I and II, with an abrupt increase during phase III. This abrupt increase was associated with initiation of photosynthesis. Pattern 3 involved phosphatidic acid (PA) first decreasing, then increasing, and finally decreasing to a low level. Pattern 1 and 3 were interrupted in chilling-sensitive seeds under low temperature, which lead a block in plastid biogenesis and accumulation of harmful PA respectively. However, they were rescued and returned to their status under a normal temperature after polyethylene glycol (PEG) osmopriming. We specifically inhibited phospholipase D (PLD)-mediated PA formation in chilling-sensitive seeds of soybean, cucumber, and pea and found their germination under low temperature was significantly improved. These results indicate that membranes undergo specific and functional reorganization of lipid composition during germination and demonstrate that PLD-mediated PA causes imibibitional chilling injury.

Transcriptome analysis uncovers key regulatory and metabolic aspects of soybean embryonic axes during germination

“…Although nuclear-encoded, the shikimate pathway and other biosynthetic processes take place at the plastids, which are largely non-functional in dry seeds. However, a recent study demonstrated that plastid biogenesis starts early in phase I of soybean germination58. Therefore, we hypothesize that newly generated plastids get promptly equipped with the shikimate and other biosynthetic pathways.…”

Osmoacondicionamiento de seis poblaciones de maíz sometidas a envejecimiento acelerado

“…et al (2006) indicaron que, durante la imbibición, el incremento del peso de las semillas de Swietenia macrophylla fue sólo significativo en las dos primeras fases; es decir, la de absorción rápida para luego no absorber agua por un cierto tiempo (hasta la protrusión de la radícula). En conductividad eléctrica las semillas de Roque B16 en remojo por 6 y 12 h superaron al testigo (5.54 µs cm -1 ), la conductividad eléctrica se basa en el principio de que conforme las semillas se deterioran, altera la permeabilidad diferencial de las membranas celulares, de manera que, al ser colocadas en una solución acuosa, la semilla menos vigorosa sufre perdida de compuestos citoplasmáticos como aminoácidos, iones y azúcares de bajo peso molecular, al ser rehidratadas las semillas deben tener la capacidad de reorganizar las membranas para evitar la pérdida de solutos (Yu et al, 2015).…”

Effects of Harvest Maturity on Chilling Injury and Storage Quality of Apricots

“…Because of chilling injury at unfavorable, low temperature, the cell membrane of cold-sensitive plants undergoes phase changes, and this affects its function and structural integrity [15]. Studies on loquats and peaches showed that the higher the unsaturated fatty acid level in the cell membrane, the higher the fluidity and stability of the cell membrane; this stability is beneficial and increases resistance of fruits to chilling injury.…”